WO2020076656A1

WO2020076656A1 - Uplink low-peak-to-average power ratio (papr) demodulation reference signal (dmrs) sequence design

Info

Publication number: WO2020076656A1
Application number: PCT/US2019/054849
Authority: WO
Inventors: Avik SENGUPTA; Alexei Davydov; Gregory V. Morozov; Sameer PAWAR; Guotong Wang
Original assignee: Intel Corporation
Priority date: 2018-10-08
Filing date: 2019-10-04
Publication date: 2020-04-16
Also published as: EP3864791A1; EP3864791A4

Abstract

Technology for a user equipment (UE) operable to generate a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR) is disclosed. The UE can generate binary DM-RS sequence in a time domain. The UE can map the binary DM-RS sequence to a 5 pi/2 binary phase shift keying (BPSK) constellation to form a pi/2 BPSK modulated binary DM-RS sequence. The UE can perform Discrete Fourier Transform (DFT) spreading and Orthogonal Frequency Division Multiplexing (OFDM) symbol generation on the pi/2 BPSK modulated binary DM-RS sequence to produce the DM-RS having the reduced PAPR. The UE can encode the DM-RS having 10 the reduced PAPR for transmission to a Next Generation NodeB (gNB) on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH).

Description

UPLINK LOW-PEAK-TO- AVERAGE POWER RATIO (PAPR) DEMODULATION REFERENCE SIGNAL (DMRS)

SEQUENCE DESIGN

BACKGROUND

[0001] Wireless systems typically include multiple User Equipment (UE) devices communicatively coupled to one or more Base Stations (BS). The one or more BSs may be Long Term Evolved (LTE) evolved NodeBs (eNB) or New Radio (NR) next generation NodeBs (gNB) that can be communicatively coupled to one or more UEs by a Third- Generation Partnership Project (3GPP) network.

[0002] Next generation wireless communication systems are expected to be a unified network/system that is targeted to meet vastly different and sometimes conflicting performance dimensions and services. New Radio Access Technology (RAT) is expected to support a broad range of use cases including Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), Mission Critical Machine Type Communication (uMTC), and similar service types operating in frequency ranges up to 100 GHz.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Features and advantages of the disclosure will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the disclosure; and, wherein:

[0004] FIG. 1 illustrates a block diagram of a Third-Generation Partnership Project (3GPP) New Radio (NR) Release 15 frame structure in accordance with an example;

[0005] FIG. 2 illustrates a demodulation reference signal (DM-RS) generation procedure in accordance with an example;

[0006] FIG. 3 illustrates New Radio (NR) Release-l5 demodulation reference signal (DM-RS) types in accordance with an example;

[0007] FIG. 4 illustrates a technique for generating computer generated (CGS) sequences in accordance with an example; [0008] FIG. 5 illustrates a technique for evaluating an autocorrelation and frequency domain shift in accordance with an example;

[0009] FIGS. 6A and 6B illustrate different cases for /)(·) for sequences with same or different lengths in accordance with an example;

[0010] FIG. 7 illustrates a frequency domain power profile of Sequence #1 and Sequence

#6 from a length 12 CGS sequence with frequency domain PAPR (FD-PAPR) minimization in accordance with an example;

[0011] FIG. 8 illustrates a length 6 CGS sequence with FD-PAPR minimization in accordance with an example;

[0012] FIG. 9 illustrates a length 12 CGS sequence with FD-PAPR minimization in accordance with an example;

[0013] FIG. 10 illustrates a length 18 CGS sequence with FD-PAPR minimization in accordance with an example;

[0014] FIG. 11 illustrates a length 24 CGS sequence with FD-PAPR minimization in accordance with an example;

[0015] FIG. 12 illustrates a frequency domain power profile of Sequence #1 and

Sequence #5 from a length 12 CGS sequence with maximum-to-second-minimum power ratio minimization in accordance with an example;

[0016] FIG. 13 illustrates a table of a length 6 CGS sequence with maximum-to-second- minimum (Max to 2nd Min) power ratio minimization in accordance with an example;

[0017] FIG. 14 illustrates a table of a length 12 CGS sequence with Max to 2nd Min power ratio minimization in accordance with an example;

[0018] FIG. 15 illustrates a table of a length 18 CGS sequence with Max to 2nd Min power ratio minimization in accordance with an example;

[0019] FIG. 16 illustrates a table of a length 24 CGS sequence with Max to 2nd Min power ratio minimization in accordance with an example;

[0020] FIG. 17 illustrates a table of a length 6 CGS sequence with a l0^th percentile power maximization in accordance with an example; [0021] FIG. 18 illustrates a table of a length 12 CGS sequence with a 10^th percentile power maximization in accordance with an example;

[0022] FIG. 19 illustrates a table of a length 18 CGS sequence with a 10^th percentile power maximization in accordance with an example;

[0023] FIG. 20 illustrates a table of a length 24 CGS sequence with a l0^th percentile power maximization in accordance with an example;

[0024] FIG. 21 illustrates a table of a length 6 CGS sequence with a 40^th percentile power maximization in accordance with an example;

[0025] FIG. 22 illustrates a table of a length 12 CGS sequence with a 40^th percentile power maximization in accordance with an example;

[0026] FIG. 23 illustrates a table of a length 18 CGS sequence with a 40^th percentile power maximization in accordance with an example;

[0027] FIG. 24 illustrates a table of a length 24 CGS sequence with a 40^th percentile power maximization in accordance with an example;

[0028] FIG. 25 illustrates a sequence having n = 1 and x = -3dB in accordance with an example;

[0029] FIG. 26 illustrates a sequence d_a and db assignment in accordance with an example;

[0030] FIG. 27 illustrates a length 6 complementary CGS sequence in accordance with an example;

[0031] FIG. 28 illustrates a length 12 complementary CGS sequence in accordance with an example;

[0032] FIG. 29 illustrates a length 18 complementary CGS sequence in accordance with an example;

[0033] FIG. 30 depicts functionality of a user equipment (UE) operable to generate a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR) in accordance with an example;

[0034] FIG. 31 depicts functionality of a user equipment (UE) operable to generate a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR) in accordance with an example;

[0035] FIG. 32 depicts a flowchart of a machine readable storage medium having instructions embodied thereon for generating a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR) in accordance with an example;

[0036] FIG. 33 illustrates an architecture of a wireless network in accordance with an example;

[0037] FIG. 34 illustrates a diagram of a wireless device (e.g., UE) in accordance with an example;

[0038] FIG. 35 illustrates interfaces of baseband circuitry in accordance with an example; and

[0039] FIG. 36 illustrates a diagram of a wireless device (e.g., UE) in accordance with an example.

[0040] Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the technology is thereby intended.

DETAILED DESCRIPTION

[0041] Before the present technology is disclosed and described, it is to be understood that this technology is not limited to the particular structures, process actions, or materials disclosed herein, but is extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular examples only and is not intended to be limiting. The same reference numerals in different drawings represent the same element. Numbers provided in flow charts and processes are provided for clarity in illustrating actions and operations and do not necessarily indicate a particular order or sequence.

DEFINITIONS

[0042] As used herein, the term“User Equipment (UE)” refers to a computing device capable of wireless digital communication such as a smart phone, a tablet computing device, a laptop computer, a multimedia device such as an iPod Touch®, or other type computing device that provides text or voice communication. The term“User Equipment (UE)” may also be referred to as a "mobile device," "wireless device," of "wireless mobile device."

[0043] As used herein, the term“Base Station (BS)” includes“Base Transceiver Stations (BTS),”“NodeBs,”“evolved NodeBs (eNodeB or eNB),”“New Radio Base Stations (NR BS) and/or“next generation NodeBs (gNodeB or gNB),” and refers to a device or configured node of a mobile phone network that communicates wirelessly with UEs.

[0044] As used herein, the term“cellular telephone network,”“4G cellular,”“Long Term Evolved (LTE),”“5G cellular” and/or“New Radio (NR)” refers to wireless broadband technology developed by the Third Generation Partnership Project (3GPP).

EXAMPLE EMBODIMENTS

[0045] An initial overview of technology embodiments is provided below and then specific technology embodiments are described in further detail later. This initial summary is intended to aid readers in understanding the technology more quickly but is not intended to identify key features or essential features of the technology nor is it intended to limit the scope of the claimed subject matter.

[0046] FIG. 1 provides an example of a 3GPP NR Release 15 frame structure. In particular, FIG. 1 illustrates a downlink radio frame structure. In the example, a radio frame 100 of a signal used to transmit the data can be configured to have a duration, T/, of 10 milliseconds (ms). Each radio frame can be segmented or divided into ten subframes llOi that are each 1 ms long. Each subframe can be further subdivided into one or multiple slots l20a, l20i, and l20x, each with a duration, T slot, of 1 / m ms, where m = 1 for l5kHz subcarrier spacing, m = 2 for 30kHz, m = 4 for 60kHz, m = 8 for 120kHz, and u = 16 for 240kHz. Each slot can include a physical downlink control channel (PDCCH) and/or a physical downlink shared channel (PDSCH).

[0047] Each slot for a component carrier (CC) used by the node and the wireless device can include multiple resource blocks (RBs) l30a, l30b, 130i, l30m, and 130h based on the CC frequency bandwidth. The CC can have a carrier frequency having a bandwidth. Each slot of the CC can include downlink control information (DCI) found in the PDCCH. The PDCCH is transmitted in control channel resource set (CORESET) which can include one, two or three Orthogonal Frequency Division Multiplexing (OFDM) symbols and multiple RBs.

[0048] Each RB (physical RB or PRB) can include 12 subcarriers (on the frequency axis) and 14 orthogonal frequency-division multiplexing (OFDM) symbols (on the time axis) per slot. The RB can use 14 OFDM symbols if a short or normal cyclic prefix is employed. The RB can use 12 OFDM symbols if an extended cyclic prefix is used. The resource block can be mapped to 168 resource elements (REs) using short or normal cyclic prefixing, or the resource block can be mapped to 144 REs (not shown) using extended cyclic prefixing. The RE can be a unit of one OFDM symbol 142 by one subcarrier (i.e., 15 kHz, 30kHz, 60kHz, l20kHz, and 240kHz) 146.

[0049] Each RE l40i can transmit two bits l50a and l50b of information in the case of quadrature phase-shift keying (QPSK) modulation. Other types of modulation may be used, such as 16 quadrature amplitude modulation (QAM) or 64 QAM to transmit a greater number of bits in each RE, or bi-phase shift keying (BPSK) modulation to transmit a lesser number of bits (a single bit) in each RE. The RB can be configured for a downlink transmission from the eNodeB to the UE, or the RB can be configured for an uplink transmission from the UE to the eNodeB.

[0050] This example of the 3GPP NR Release 15 frame structure provides examples of the way in which data is transmitted, or the transmission mode. The example is not intended to be limiting. Many of the Release 15 features will evolve and change in the 5G frame structures included in 3GPP LTE Release 15, MulteFire Release 1.1, and beyond. In such a system, the design constraint can be on co-existence with multiple 5G numerologies in the same carrier due to the coexistence of different network services, such as eMBB (enhanced Mobile Broadband), mMTC (massive Machine Type

Communications or massive IoT) and URLLC (Ultra Reliable Low Latency

Communications or Critical Communications). The carrier in a 5G system can be above or below 6GHz. In one embodiment, each network service can have a different numerology. Low PAPR Reference Signal Design for Coverage Enhancement Waveforms

[0051] In New Radio (NR), pi/2-binary phase shift keying (BPSK) modulation can be supported for Discrete Fourier Transform (DFT) spread Orthogonal Frequency Division Multiplexing (OFDM) waveforms to achieve a low PAPR data transmission to enable coverage enhancement for a power limited user equipment (UE). However, a Zadoff-chu sequence based DMRS has a ldB-l.5 dB higher PAPR as compared to pi/2 BPSK modulated DFT-S-OFDM PUSCH data symbols. In this case, a low PAPR UE would be coverage limited due to the higher PAPR of reference signal, e.g., DMRS.

[0052] In one configuration, a NR multiple-input multiple-output (MIMO) low PAPR reference signal design is described. For example, four different

methodologies/frameworks are defined herein to design low PAPR reference signals, including (1) using Golay sequences; (2) using generalized pi/M-BPSK and QPSK modulations; (3) using DFT-spread ZC sequences; and (4) block based concatenation of base sequences. Thus, the methodologies/frameworks defined herein can be used to simultaneously provide low PAPR as well as better channel estimation performance.

[0053] In one example, a DM-RS sequence of length L can be defined in the time domain by using a Golay code. For example, a Golay sequence of length N denoted as b’(i) can be cyclically extended to achieve the desired sequence length L, by using the following expression:

b(i) = b’((i + offset_T)mod N), i = 0,1,... ,L-l

where N is selected as a maximum Golay sequence length of N <= L. The Golay sequence can be cyclically shifted prior the extension according to the parameter offset T that can be indicated to the UE via signaling.

[0054] In one example, N can be selected as a minimum Golay sequence length of N >=L. In this case, the Golay sequence can be punctured to achieve the desired sequence length of L. The same cyclic shift can be applied to the Golay sequence as in the previous example by using parameter offset T.

[0055] In one example, after the extension / puncturing step, the Golay sequence can be modulated by using pi/2 BPSK modulation according to:

[0056] In one example, the Golay sequence after pi/2 BPSK modulation can be block wise repeated R times to achieve the length of L*R. To obtain multiple orthogonal DM- RS sequences, orthogonal cover codes w(j) can be used across different blocks d(i) as follows: r(i) = d(i) * w(floor(i/L)).

[0057] In one example, the cover code w(j) can be according to vectors from a Hadamard matrix. In another example, the orthogonal cover code can be according to a vector from a discrete Fourier transform (DFT) matrix. The actual vector from the Hadamard or DFT matrix can be indicated to the UE by signaling.

[0058] In one example, a blockwise repeated sequence can be converted to a frequency domain by using a fast Fourier transform (FFT) operation. The FFT operation can applied to a groups of B blocks, i.e., the FFT is taken independently for each k-th group of samples of r(i) satisfying the following condition:

t = FFT(r(i)), where index L*R / B *(k-l) <=i < L*R / B * k.

[0059] In one example, the sequence t is then mapped to allocated resource elements (subcarrier) of the system bandwidth. The sequence can be cyclically shifted prior to mapping to the allocated resource elements.

[0060] FIG. 2 illustrates an example of a demodulation reference signal (DM-RS) generation procedure. In a first action, a Golay sequence denoted as b(i) can be generated. In a second action, an extension or truncation (cyclic shift) can be performed. In a third action, a pi/2 BPSK modulation d(i) can be performed. In a fourth action, a blockwise repetition can be performed. In a fifth action, a cover code can be applied over the block(s). In a sixth action, an FFT can be performed. In a seventh action, a mapping to allocated resources (cyclic shift) can be performed. In a seventh action, an IFFT action can be performed.

[0061] In one example, the sequence of the above actions can be different depending on implementation. For example, the pi/2 BPSK modulation in the third action the and cyclic extension / puncturing in the second action can be different. [0062] In one example, the DM-RS signal can be generated using a“generalized modulation” of BPSK and QPSK. One solution to design a low PAPR reference signal is to“follow the data path”, i.e., generate a random binary signal using a Gold code and modulate the random binary signal using pi/2 BPSK before DFT spreading, which can guarantee that the DMRS PAPR is the same as pi/2 BPSK modulation DFT-s-OFDM PUSCH data symbols. However, since the reference signal is designed in the time- domain, the reference signal can have amplitude variations in the frequency domain. This results in potential loss in channel estimation performance depending on the channel statistics (frequency selectivity).

[0063] In this example, the framework can be generalized to two cases. A first case can correspond to BPSK modulated with pi/3 or pi/4 or in general pi/M, such that the DMRS design balances between two metrics, the channel estimation (constant modulus in frequency domain) performance and time domain PAPR. A second case can correspond to QPSK modulated with pi/3 or pi/4 or in general pi/M, such that the DMRS design balances between two metrics, the channel estimation (constant modulus in frequency domain) performance and time domain PAPR.

[0064] In one example, the DM-RS signal can be generated using a DFT spread ZC sequence. In this example, a DMRS reference signal sequence can be designed using DFT spreading ofZC sequences, such as physical uplink shared channel (PUSCH) data symbols.

[0065] In one example, the DM-RS signal can be generated using“block concatenation” of a base sequence(s) design. In this example, a base reference signal sequence or sequences can be designed using any of the techniques described herein, as well as computer generated sequences, and generalizing the design to other lengths using block- wise concatenation. Sequences that have low PAPR can be identified while

simultaneously achieving the almost constant modulus in the frequency domain. After design a set of such good base sequences, sequences for other lengths can be generated using block wise concatenation of subsets of these base sequences. The low PAPR and almost constant modulus in the frequency domain can be then maintained using block wise phase modulations. The concatenations can be done either in the time or frequency domain. [0066] In one configuration, a technique is described for designing a low PAPR DM-RS while simultaneously achieving good channel estimation performance via an almost constant modulus signal in the frequency domain. In one example, the DMRS can be generated using Golay sequences. In another example, the DRMS can be generated using generalized pi/M modulation of BPSK or QPSK. In yet another example, a value of integer M can be selected to satisfy a good PAPR in the time domain, as well as almost constant modulus envelop in the frequency domain.

[0067] In one example, the DMRS signal can be generated using DFT spreading of ZC sequences. In another example, the DMRS signal can be generated using block concatenation of generated base sequences. Further, block wise phase modulations can be applied to achieve low PAPR and almost constant modulation in the frequency domain.

Uplink Low-PAPR DMRS Sequence Design

[0068] In one example, for PUSCH/PUCCH DMRS for pi/2 modulation, new DMRS sequences are specified in Rel.16 NR to reduce the PAPR to the same level as for data symbols, with a consideration of channel estimation performance and cross correlation performance.

[0069] In Release-l5 NR, for the case of pi/2 BPSK modulated DFT-S-OFDM based physical uplink shared channel (PUSCH) or physical uplink control channel (PUCCH), the corresponding demodulation reference signals (DMRSs) can be generated in the frequency domain based on computer generated sequences (CGS) mapped to a QPSK constellation for the case of resource allocation of up to 4 PRBs, or based on extended Zadoff-Chu sequences for larger resource allocations. For the case when pi/2 BPSK modulation possibly with time or frequency domain pulse-shaping is used for data, the PAPR of the DMRS can be degraded compared to the data.

[0070] In one configuration, a NR multiple-input multiple-output (MIMO) low PAPR reference signal design is described herein. More specifically, based on the design considerations described above, techniques for low PAPR reference signal design for DFT-S-OFDM based PUSCH/PUCCH with pi/2 BPSK modulation are described herein.

[0071] FIG. 3 illustrates an example of New Radio (NR) Release-l5 demodulation reference signal (DM-RS) types. In NR Release-l5, two different DM-RS types are used, namely Type-l and Type-2 DM-RS. For a single symbol case, Type 1 DMRS can use a comb-2 structure with 2 CDM-Groups and length-2 FD-OCC per pair of alternating REs in each CDM-Group, while Type 2 DMRS can use a comb-3 structure with 3 CDM- Groups and length-2 FD-OCC per pair of adjacent REs in each CDM-Group. The length- 2 FD-OCC is given by [i i_{, i -i}] .

[0072] In one example, for uplink DMRS, when a DFT-S-OFDM waveform is used, only Type 1 DMRS is used in Rel-l5 NR. For this case, the DMRS base sequence can be generated in the frequency domain according to a first case or a second case. The first case (small resource allocation) can be for base sequences of length {6, 12, 18, 24} computer generated sequences mapped to QPSK constellation. For length 30, the sequence also has a constant modulus and is based on points chosen from the unit circle in an in-phase and quadrature (I/Q) plane. With respect to the second case (larger resource allocation), for base sequences of length 36 or larger, cyclically extended Zadoff-Chu sequence can be used.

[0073] In one example, the base sequences are divided into u e {1, ..., 30} each containing a single base sequence for sequence length up to 5N 12 (where N = 12 for NR) and two base sequences for larger sequence length where v e {0,1} is the base sequence number. The DMRS sequences are generated in the frequency domain i.e., they are not DFT-spread and are constant modulus signals in the frequency domain. In the case when pi/2-BPSK is used for modulating the PUSCH/PUCCH, the PAPR of the data can become much lower than of the ZC or CGS based DMRS. A sequence design is described herein for the case of PUSCH/PUCCH when pi/2 BPSK modulation and a DFT-s-OFDM waveform are used.

[0074] In one example, for the case of Release-l6 NR, the DMRS for pi/2 BPSK modulated PUSCH and PUCCH can be generated in the time domain as a binary sequence, mapped to a pi/2 BPSK constellation and then transmitted after DFT-spreading and OFDM symbol generation, similar to PUSCH/PUCCH. For this case, a Type 1 DMRS structure in frequency domain, with the following sequence options can be used:

A first option (resource allocations of 1-4 PRB) in which sequence lengths {6, 12, 18 and 24} uses binary CGS sequences, or a second option (resource allocations of more than 4 PRB) in which sequence lengths of 30 and above uses PN sequences based on a Gold Code.

[0075] In one example, the mapping of the binary sequence b(i) to pi/2 BPSK sequence d(i) is defined according to the following:

After DFT-spreading of the pi/2-BPSK modulated DMRS sequence, frequency domain pulse/spectrum shaping can be applied. Alternatively, time domain spectrum shaping can be applied before DFT-spreading.

Sequence Design for First Option (Small Resource Allocation 1-4 PRB):

[0076] FIG. 4 illustrates an example of a technique for generating computer generated (CGS) sequences, for the case of resource allocation of less than 5 PRBs. The technique can involve generating all binary sequences of length L, ordering all sequences based on a value of a metric, choosing a first N sequences, initializing a set with a first sequence, and then choosing another sequence.

[0077] As an example, the smallest i.e., length 6 sequence design can be started with. Then based on the sequences designed in this case, the length 12 sequences can be designed such that cross-correlation between chosen length 6 and length 12 sequences are minimized. Similarly, for a length 18 sequence design, cross-correlation between length chosen 6, 12 sequences and length 18 sequences are minimized and for length 24, cross correlation between chosen length 6, 12, 18 sequences and length 24 sequences are minimized.

[0078] In one example, the function xCorr( ) can measure the maximum linear cross correlation in the time domain after OFDM symbol generation between two sequences. Furthermore, the maximum linear cross-correlation between first sequence and all possible shifted and zero padded versions (in frequency domain) of second sequence where the shifts are in multiples of 6 subcarriers and replicates the impact of non overlapping frequency allocation for all sequences. [0079] FIG. 5 illustrates an example of a technique for evaluating a cross-correlation under a frequency domain shift of one sequence. A function f_T (·) denotes a shifting of the sequence in the frequency domain. In one example, the shifting can be done after mapping the complex frequency domain sequence to alternate sub-carriers after multiplying with OCC i.e., after Type 1 DMRS resource mapping. The reference point is subcarrier zero of the lowest numbered sub-carrier in the UE’s uplink resource allocation.

[0080] FIGS. 6A and 6B illustrate an example of different cases for f_T(·) for sequences with same or different lengths. This can be generalized to sequences of any two lengths. The sequences are then mapped to the subcarriers based on Type 1 DMRS mapping and linear cross-correlation is calculated in the time domain after OFDM symbol generation.

[0081] In one example, in addition to linear cross-correlation of a sequence with equal and smaller length sequences, circular cross correlation may also be evaluated. Final cross correlation i.e., max(xCorr(·)) for a given sequence is the maximum linear cross correlation values among all shifts and all chosen sequences of shorter length. Finally the sequence with minimum of this value is chosen in each iteration.

[0082] In one example, the sequence design in this embodiment depends on the values of the metric M_l which is chosen. The metric can be chosen to optimize sequence design with respect to improved channel estimation performance and PAPR.

[0083] In one example, the metric can be chosen to be the minimization of frequency domain PAPR (FD-PAPR). The FD-PAPR is defined as the ratio of maximum to mean power of the pi/2 BPSK modulated sequence in the frequency domain after DFT spreading.

[0084] FIG. 7 illustrates an example of a frequency domain power profile of Sequence #1 and Sequence #6 from a length 12 CGS sequence with FD-PAPR minimization (shown in FIG. 9). In some cases, minimizing FD-PAPR still leaves the option for overall non-flat power profile even with some zero power samples.

[0085] FIGS. 8-11 illustrate exemplary tables of sequences generated using this metric with K=30 sequences each for lengths L = {6, 12, 18 and 24}. For example, FIG. 8 illustrates an exemplary table of a length 6 CGS sequence with FD-PAPR minimization, FIG. 9 illustrates an exemplary table of a length 12 CGS sequence with FD-PAPR minimization, FIG. 10 illustrates an exemplary table of a length 18 CGS sequence with FD-PAPR minimization, and FIG. 11 illustrates an exemplary table of a length 24 CGS sequence with FD-PAPR minimization.

[0086] In one example, the metric can be minimization of the following ratio:

where P_l is the vector of powers of the reference signal sequence in the frequency domain after pi/2 BPSK modulation and DFT-spreading. The value of p can be determined by: sorting the values in /{ in ascending order; and choosing the n-th value in this sorted set and assign to p. The value of n can be {2, 3, 4, 5..}. The significance of n is0 that it allows the frequency domain signal to possibly have n number of zero power

samples.

[0087] FIG. 12 illustrates an example of a frequency domain power profile of Sequence #1 and Sequence #5 from a length 12 CGS sequence with maximum-to-second-minimum (Max to 2nd Min) power ratio minimization (shown in FIG. 14). In this example, the5 metric can be minimized with n=2. Further, when the metric is minimized with n=2, one zero power sample is still allowed in the frequency domain.

[0088] FIGS. 13-16 illustrate exemplary tables of sequences generated using this metric with K=30 sequences each for lengths L = {6, 12, 18 and 24} and n=2. For example, FIG. 13 illustrates an exemplary table of a length 6 CGS sequence with maximum-to-second-0 minimum (Max to 2nd Min) power ratio minimization, FIG. 14 illustrates an exemplary table of a length 12 CGS sequence with Max to 2nd Min power ratio minimization, FIG. 15 illustrates an exemplary table of a length 18 CGS sequence with Max to 2nd Min power ratio minimization, and FIG. 16 illustrates an exemplary table of a length 24 CGS sequence with Max to 2nd Min power ratio minimization.

5 [0089] In one example, the metric can be the maximization of the P^th percentile power of the frequency domain samples of the reference signal after pi/2-BPSK modulation and DFT-spreading wherein P = {10, 20, 30, 40, 50}.

[0090] FIGS. 17-20 illustrate exemplary tables of sequences generated using this metric with K=30 sequences each for lengths L = {6, 12, 18 and 24} and P=l0. For example, FIG. 17 illustrates an exemplary table of a length 6 CGS sequence with a l0^th percentile power maximization, FIG. 18 illustrates an exemplary table of a length 12 CGS sequence with a l0^th percentile power maximization, FIG. 19 illustrates an exemplary table of a length 18 CGS sequence with a l0^th percentile power maximization, and FIG. 20 illustrates an exemplary table of a length 24 CGS sequence with a l0^th percentile power maximization.

[0091] FIGS. 21-24 illustrate exemplary tables of sequences generated using this metric with K=30 sequences each for lengths L = {6, 12, 18 and 24} and P=40. For example, FIG. 21 illustrates an exemplary table of a length 6 CGS sequence with a 40^th percentile power maximization, FIG. 22 illustrates an exemplary table of a length 12 CGS sequence with a 40^th percentile power maximization, FIG. 23 illustrates an exemplary table of a length 18 CGS sequence with a 40^th percentile power maximization, and FIG. 24 illustrates an exemplary table of a length 24 CGS sequence with a 40^th percentile power maximization.

[0092] In one example, the value K of number of sequence groups can be less than 30 (as in Release-l5 NR).

[0093] In another example, the sequences can be selected by computing a cyclic auto correlation of sequence d(i) according to the following:

[0094] The set of sequence can be selected to searching the sequence that‘n’ non-zero elements R(j) for j¹0 which has x times value lower that R(j) for j=0, i.e. R(j)/ R(0) < x. The value of‘n’ can vary according to the following order‘n’ = 0, 1, 2, etc.

[0095] FIG. 25 illustrates an example of a sequence having n = 1 and x = -3dB. The value of‘n’ can vary according to the following order‘n’ = 0, 1, 2, etc., and R(j)/ R(0) < x.

[0096] In one example, the sequence can be selected to minimize the sum of the elements of signal auto correlation function, as follows:

[0097] In one example, based on the CGS sequences generated using any of the above metrics, additional sequences can be generated using the following operations on the sequence: (1) Frequency domain cyclic shift of the generated sequence; (2) Time domain cyclic shifts of the pi/2 BPSK modulated sequence, i.e. cF(j) = c/(mod(/ + offset, n ) or (3) Repetition of the generated sequence in time/frequency. With respect to (1), in one example, the cyclic shift which is a multiple of 6 subcarriers can be excluded in the generation procedure to avoid high cross correlation between partially overlapping resource allocation in the frequency domain. With respect to (2), in one example, the cyclic shift defined by a parameter offset which has value lower the pre-determined threshold f and larger than pre-determined threshold‘n-y’ should not be considered to accommodate propagation delay difference between different UEs in different cells.

[0098] FIG. 26 illustrates an example of complementary DM-RS sequences d_a and db assigned to DM-RS symbols. In one example, with respect to complementary sequences, for the case of two-symbol DMRS i.e., DMRS sequences d_a and db occupying two adjacent symbols can be used. In another example, for a single symbol DM-RS configuration with additional DM-RS(s) in the slot, complementary sequences a, b, etc. can be used where d_a is assigned to front loaded DM-RS and db is assigned to the first additional DM-RS. In case of more than one additional DM-RS, the pattern can be repeated wherein d_a can be assigned to the third DM-RS symbol in the slot and db can be assigned to the fourth DM-RS symbol in the slot. Alternately other complementary sequences d_c and dd can be used in the third and fourth DM-RS symbol respectively. The complimentary DM-RS sequence can be defined to have a sum of auto-correlation function close to the delta function. For example, for two sequence d_a and db, the sum of auto-correlation function can be defined as follows:

[0099] In one example, the following conditional should be fulfilled, where x is pre determined threshold.

[00100] In another example, x = 0.

[00101] In one example, such complementary sequences corresponding to each sequence generated in an exemplary table of a length 6 CGS sequence with Max to 2nd Min power ratio minimization and n=2 (FIG. 13), an exemplary table of a length 12 CGS sequence with Max to 2nd Min power ratio minimization and n=2 (FIG. 14), and an exemplary table of a length 18 CGS sequence with Max to 2nd Min power ratio minimization and n=2 (FIG. 15) can be defined.

[00102] FIG. 27 illustrates a length 6 complementary CGS sequence in relation to a length 6 CGS sequence with Max to 2nd Min power ratio minimization and n=2 (FIG. 13), FIG. 28 illustrates a length 12 complementary CGS sequence in relation to a length 12 CGS sequence with Max to 2nd Min power ratio minimization and n=2 (FIG. 14), and FIG. 29 illustrates a length 18 complementary CGS sequence in relation to a length 18 CGS sequence with Max to 2nd Min power ratio minimization and n=2 (FIG. 15),

Sequence Design for Second Option (Larger Resource Allocation):

[00103] In one example, for pi/2 BPSK modulated PUSCH or PUCCH DMRS with resources allocations larger than 4 PRBs, Gold Code based binary PN sequences as in Release-l5 NR CP-OFDM based PUSCH DMRS can be used with the following initialization:

[00104] In one example, for a non-pi/2 BPSK modulated case, for large resource allocations, an M-PSK constellation (with numbered constellation points) can be used in the time domain along with a binary Gold Code based PN sequence with c init as above configured to each UE. In one example, a UE can start modulation with a I^st constellation point. In another example, the constellation starting point can be configured to the UE by downlink control information (DCI). When a sequence bit is 1, the bit can be modulated using a next clockwise constellation point. If a bit is zero, the bit can be modulated using a next anti-clockwise point. The modulation of next bit can be clockwise or anti clockwise with respect to the current state (constellation point).

[00105] In one configuration, a technique for low PAPR reference signal generation in an uplink is defined, when pi/2 BPSK modulation is used along with DFT-S-OFDM waveform or transform precoding. In one example, a binary DMRS sequence can be generated in the time domain, modulated by pi/2 BPSK and transform precoded before an OFDM transmission. In another example, Type 1 DMRS can be considered for a PUSCH and a DMRS for PUCCH format 3 and 4 with no comb structure is applicable.

[00106] In one example, for resource allocations up to 4 PRB for a PUSCH,

corresponding to sequences of length 6,12,18,24 and for a PUCCH corresponding to up to 2 PRB allocations with sequence lengths 12, 24, computer generated sequences (CGS) can be used. In another example, for a PUSCH with greater than 4 PRB allocation and a PUCCH with greater than 2 PRB allocation, a PN sequence can be used.

[00107] In one example, a technique to generate a CGS sequence is based on a metric design. The metric can be minimizing FD-PAPR, FD Max to n-th Min Power ratio with n=l,2,3,4,5 or maximizing P-th Percentile FD-Power where P=l 0,20,30,40,50. In another example, FD or TD cyclic shifts can be used to generate additional sequences. In yet another example, complementary sequences can be used. In a further example, non-pi/2 BPSK modulated sequences i.e., sequences differentially modulated with M-PSK can be used.

[00108] Another example provides functionality 3000 of a user equipment (UE) operable to generate a demodulation reference signal (DM-RS) having a reduced peak-to- average power ratio (PAPR), as shown in FIG. 30. The UE can comprise one or more processors configured to generate, at the UE, a binary DM-RS sequence in a time domain, as in block 3010. The UE can comprise one or more processors configured to map, at the UE, the binary DM-RS sequence to a pi/2 binary phase shift keying (BPSK) constellation to form a pi/2 BPSK modulated binary DM-RS sequence, as in block 3020. The UE can comprise one or more processors configured to perform, at the UE, Discrete Fourier Transform (DFT) spreading and Orthogonal Frequency Division Multiplexing (OFDM) symbol generation on the pi/2 BPSK modulated binary DM-RS sequence to produce the DM-RS having the reduced PAPR, as in block 3030. The UE can comprise one or more processors configured to encode, at the UE, the DM-RS having the reduced PAPR for transmission to a Next Generation NodeB (gNB) on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH), as in block 3040. In addition, the UE can comprise a memory interface configured to send to a memory the binary DM- RS sequence.

[00109] Another example provides functionality 3100 of a user equipment (UE) operable to generate a demodulation reference signal (DM-RS) having a reduced peak-to- average power ratio (PAPR), as shown in FIG. 31. The UE can comprise one or more processors configured to generate, at the UE, a binary DM-RS sequence in a time domain, as in block 3110. The UE can comprise one or more processors configured to apply, at the UE, a pi/2 binary phase shift keying (BPSK) modulation and a Discrete Fourier

Transform (DFT) spread Orthogonal Frequency Division Multiplexing (OFDM) waveform or transform precoding on the binary DM-RS sequence to produce the DM-RS having the reduced PAPR, as in block 3120. The UE can comprise one or more processors configured to encode, at the UE, the DM-RS having the reduced PAPR for transmission to a Next Generation NodeB (gNB) on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH), as in block 3130. In addition, the UE can comprise a memory interface configured to send to a memory the binary DM-RS sequence.

[00110] Another example provides at least one machine readable storage medium having instructions 3200 embodied thereon for generating a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR), as shown in FIG. 32. The instructions can be executed on a machine, where the instructions are included on at least one computer readable medium or one non-transitory machine readable storage medium. The instructions when executed by one or more processors of a user equipment (UE) perform: generating, at the UE, a binary DM-RS sequence in a time domain, as in block 3210. The instructions when executed by the one or more processors perform: mapping, at the UE, the binary DM-RS sequence to a pi/2 binary phase shift keying (BPSK) constellation to form a pi/2 BPSK modulated binary DM-RS sequence, as in block 3220. The instructions when executed by the one or more processors perform: performing, at the UE, Discrete Fourier Transform (DFT) spreading and Orthogonal Frequency Division Multiplexing (OFDM) symbol generation on the pi/2 BPSK modulated binary DM-RS sequence to produce the DM-RS having the reduced PAPR, as in block 3230. The instructions when executed by the one or more processors perform: encoding, at the UE, the DM-RS having the reduced PAPR for transmission to a Next Generation NodeB (gNB) on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH), as in block 3240.

[00111] FIG. 33 illustrates an architecture of a system 3300 of a network in accordance with some embodiments. The system 3300 is shown to include a user equipment (UE) 3301 and a UE 3302. The UEs 3301 and 3302 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks), but may also comprise any mobile or non-mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, or any computing device including a wireless communications interface.

[00112] In some embodiments, any of the UEs 3301 and 3302 can comprise an Internet of Things (IoT) UE, which can comprise a network access layer designed for low-power IoT applications utilizing short-lived UE connections. An IoT UE can utilize

technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or IoT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network describes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the IoT network.

[00113] The UEs 3301 and 3302 may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) 3310— the RAN 3310 may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), aNextGen RAN (NG RAN), or some other type of RAN. The UEs 3301 and 3302 utilize connections 3303 and 3304, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections 3303 and 3304 are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code division multiple access (CDMA) network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth generation (5G) protocol, a New Radio (NR) protocol, and the like.

[00114] In this embodiment, the UEs 3301 and 3302 may further directly exchange communication data via a ProSe interface 3305. The ProSe interface 3305 may alternatively be referred to as a sidelink interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH).

[00115] The UE 3302 is shown to be configured to access an access point (AP) 3306 via connection 3307. The connection 3307 can comprise a local wireless connection, such as a connection consistent with any IEEE 3402.15 protocol, wherein the AP 3306 would comprise a wireless fidelity (WiFi®) router. In this example, the AP 3306 is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below).

[00116] The RAN 3310 can include one or more access nodes that enable the connections 3303 and 3304. These access nodes (ANs) can be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), next Generation NodeBs (gNB), RAN nodes, and so forth, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). The RAN 3310 may include one or more RAN nodes for providing macrocells, e.g., macro RAN node 3311, and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), e.g., low power (LP) RAN node 3312.

[00117] Any of the RAN nodes 3311 and 3312 can terminate the air interface protocol and can be the first point of contact for the UEs 3301 and 3302. In some embodiments, any of the RAN nodes 3311 and 3312 can fulfill various logical functions for the RAN 3310 including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management.

[00118] In accordance with some embodiments, the UEs 3301 and 3302 can be configured to communicate using Orthogonal Frequency-Division Multiplexing (OFDM) communication signals with each other or with any of the RAN nodes 3311 and 3312 over a multi carrier communication channel in accordance various communication techniques, such as, but not limited to, an Orthogonal Frequency-Division Multiple Access (OFDMA) communication technique (e.g., for downlink communications) or a Single Carrier Frequency Division Multiple Access (SC-FDMA) communication technique (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers.

[00119] In some embodiments, a downlink resource grid can be used for downlink transmissions from any of the RAN nodes 3311 and 3312 to the UEs 3301 and 3302, while uplink transmissions can utilize similar techniques. The grid can be a time- frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a time-frequency plane

representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time- frequency unit in a resource grid is denoted as a resource element. Each resource grid comprises a number of resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block comprises a collection of resource elements; in the frequency domain, this may represent the smallest quantity of resources that currently can be allocated. There are several different physical downlink channels that are conveyed using such resource blocks.

[00120] The physical downlink shared channel (PDSCH) may carry user data and higher-layer signaling to the UEs 3301 and 3302. The physical downlink control channel (PDCCH) may carry information about the transport format and resource allocations related to the PDSCH channel, among other things. It may also inform the UEs 3301 and 3302 about the transport format, resource allocation, and H-ARQ (Hybrid Automatic Repeat Request) information related to the uplink shared channel. Typically, downlink scheduling (assigning control and shared channel resource blocks to the UE 3302 within a cell) may be performed at any of the RAN nodes 3311 and 3312 based on channel quality information fed back from any of the UEs 3301 and 3302. The downlink resource assignment information may be sent on the PDCCH used for (e.g., assigned to) each of the UEs 3301 and 3302.

[00121] The PDCCH may use control channel elements (CCEs) to convey the control information. Before being mapped to resource elements, the PDCCH complex-valued symbols may first be organized into quadruplets, which may then be permuted using a sub-block interleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine sets of four physical resource elements known as resource element groups (REGs). Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of the downlink control information (DCI) and the channel condition. There can be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g., aggregation level, L=l, 2,

4, or 34).

[00122] Some embodiments may use concepts for resource allocation for control channel information that are an extension of the above-described concepts. For example, some embodiments may utilize an enhanced physical downlink control channel

(EPDCCH) that uses PDSCH resources for control information transmission. The EPDCCH may be transmitted using one or more enhanced the control channel elements (ECCEs). Similar to above, each ECCE may correspond to nine sets of four physical resource elements known as an enhanced resource element groups (EREGs). An ECCE may have other numbers of EREGs in some situations.

[00123] The RAN 3310 is shown to be communicatively coupled to a core network (CN) 3320— via an Sl interface 3313. In embodiments, the CN 3320 may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN. In this embodiment the Sl interface 3313 is split into two parts: the Sl-U interface 3314, which carries traffic data between the RAN nodes 3311 and 3312 and the serving gateway (S-GW) 3322, and the Sl-mobility management entity (MME) interface 3315, which is a signaling interface between the RAN nodes 3311 and 3312 and MMEs 3321.

[00124] In this embodiment, the CN 3320 comprises the MMEs 3321, the S-GW 3322, the Packet Data Network (PDN) Gateway (P-GW) 3323, and a home subscriber server (HSS) 3324. The MMEs 3321 may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSN). The MMEs 3321 may manage mobility aspects in access such as gateway selection and tracking area list management. The HSS 3324 may comprise a database for network users, including subscription-related information to support the network entities’ handling of

communication sessions. The CN 3320 may comprise one or several HSSs 3324, depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS 3324 can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc.

[00125] The S-GW 3322 may terminate the Sl interface 3313 towards the RAN 3310, and routes data packets between the RAN 3310 and the CN 3320. In addition, the S-GW

3322 may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement.

[00126] The P-GW 3323 may terminate an SGi interface toward a PDN. The P-GW

3323 may route data packets between the EPC network 3323 and external networks such as a network including the application server 3330 (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface 3325. Generally, the application server 3330 may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS Packet Services (PS) domain, LTE PS data services, etc.). In this embodiment, the P-GW 3323 is shown to be communicatively coupled to an application server 3330 via an IP communications interface 3325. The application server 3330 can also be configured to support one or more communication services (e.g., Voice over-Internet Protocol (VoIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UEs 3301 and 3302 via the CN 3320.

[00127] The P-GW 3323 may further be a node for policy enforcement and charging data collection. Policy and Charging Enforcement Function (PCRF) 3326 is the policy and charging control element of the CN 3320. In a non-roaming scenario, there may be a single PCRF in the Home Public Land Mobile Network (HPLMN) associated with a UE’s Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with local breakout of traffic, there may be two PCRFs associated with a UE’s IP-CAN session: a Home PCRF (H-PCRF) within a HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF 3326 may be communicatively coupled to the application server 3330 via the P-GW 3323. The application server 3330 may signal the PCRF 3326 to indicate a new service flow and select the appropriate Quality of Service (QoS) and charging parameters. The PCRF 3326 may provision this rule into a Policy and Charging Enforcement Function (PCEF) (not shown) with the appropriate traffic flow template (TFT) and QoS class of identifier (QCI), which commences the QoS and charging as specified by the application server 3330.

[00128] FIG. 34 illustrates example components of a device 1100 in accordance with some embodiments. In some embodiments, the device 1100 may include application circuitry 3402, baseband circuitry 3404, Radio Frequency (RF) circuitry 3406, front-end module (FEM) circuitry 3408, one or more antennas 3410, and power management circuitry (PMC) 3412 coupled together at least as shown. The components of the illustrated device 1100 may be included in a UE or a RAN node. In some embodiments, the device 1100 may include less elements (e.g., a RAN node may not utilize application circuitry 3402, and instead include a processor/controller to process IP data received from an EPC). In some embodiments, the device 1100 may include additional elements such as, for example, memory /storage, display, camera, sensor, or input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device (e.g., said circuitries may be separately included in more than one device for Cloud-RAN (C-RAN) implementations).

[00129] The application circuitry 3402 may include one or more application processors. For example, the application circuitry 3402 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with or may include memory /storage and may be configured to execute instructions stored in the memory /storage to enable various applications or operating systems to run on the device 1100. In some embodiments, processors of application circuitry 3402 may process IP data packets received from an EPC. [00130] The baseband circuitry 3404 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 3404 may include one or more baseband processors or control logic to process baseband signals received from a receive signal path of the RF circuitry 3406 and to generate baseband signals for a transmit signal path of the RF circuitry 3406. Baseband processing circuity 3404 may interface with the application circuitry 3402 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 3406. For example, in some embodiments, the baseband circuitry 3404 may include a third generation (3G) baseband processor 3404a, a fourth generation (4G) baseband processor 3404b, a fifth generation (5G) baseband processor 3404c, or other baseband processor(s) 3404d for other existing generations, generations in development or to be developed in the future (e.g., second generation (2G), sixth generation (6G), etc.). The baseband circuitry 3404 (e.g., one or more of baseband processors 3404a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 3406. In other embodiments, some or all of the functionality of baseband processors 3404a-d may be included in modules stored in the memory 3404g and executed via a Central Processing Unit (CPU) 3404e. The radio control

functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments,

modulation/demodulation circuitry of the baseband circuitry 3404 may include Fast- Fourier Transform (FFT), precoding, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 3404 may include convolution, tail-biting convolution, turbo, Viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

[00131] In some embodiments, the baseband circuitry 3404 may include one or more audio digital signal processor(s) (DSP) 3404f. The audio DSP(s) 3404f may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 3404 and the application circuitry 3402 may be implemented together such as, for example, on a system on a chip (SOC).

[00132] In some embodiments, the baseband circuitry 3404 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 3404 may support communication with an evolved universal terrestrial radio access network (EUTRAN) or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 3404 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

[00133] RF circuitry 3406 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 3406 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 3406 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 3408 and provide baseband signals to the baseband circuitry 3404. RF circuitry 3406 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 3404 and provide RF output signals to the FEM circuitry 3408 for transmission.

[00134] In some embodiments, the receive signal path of the RF circuitry 3406 may include mixer circuitry 3406a, amplifier circuitry 3406b and filter circuitry 3406c. In some embodiments, the transmit signal path of the RF circuitry 3406 may include filter circuitry 3406c and mixer circuitry 3406a. RF circuitry 3406 may also include synthesizer circuitry 3406d for synthesizing a frequency for use by the mixer circuitry 3406a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 3406a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 3408 based on the synthesized frequency provided by synthesizer circuitry 3406d. The amplifier circuitry 3406b may be configured to amplify the down-converted signals and the filter circuitry 3406c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 3404 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 3406a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

[00135] In some embodiments, the mixer circuitry 3406a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 3406d to generate RF output signals for the FEM circuitry 3408. The baseband signals may be provided by the baseband circuitry 3404 and may be filtered by filter circuitry 3406c.

[00136] In some embodiments, the mixer circuitry 3406a of the receive signal path and the mixer circuitry 3406a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuitry 3406a of the receive signal path and the mixer circuitry 3406a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 3406a of the receive signal path and the mixer circuitry 3406a may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuitry 3406a of the receive signal path and the mixer circuitry 3406a of the transmit signal path may be configured for super-heterodyne operation.

[00137] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 3406 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 3404 may include a digital baseband interface to communicate with the RF circuitry 3406.

[00138] In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the

embodiments is not limited in this respect.

[00139] In some embodiments, the synthesizer circuitry 3406d may be a fractional-N synthesizer or a fractional N/N+l synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 3406d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

[00140] The synthesizer circuitry 3406d may be configured to synthesize an output frequency for use by the mixer circuitry 3406a of the RF circuitry 3406 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 3406d may be a fractional N/N+l synthesizer.

[00141] In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 3404 or the applications processor 3402 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the applications processor 3402.

[00142] Synthesizer circuitry 3406d of the RF circuitry 3406 may include a divider, a delay -locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+l (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[00143] In some embodiments, synthesizer circuitry 3406d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry 3406 may include an IQ/polar converter.

[00144] FEM circuitry 3408 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 3410, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 3406 for further processing. FEM circuitry 3408 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 3406 for transmission by one or more of the one or more antennas 3410. In various embodiments, the amplification through the transmit or receive signal paths may be done solely in the RF circuitry 3406, solely in the FEM 3408, or in both the RF circuitry 3406 and the FEM 3408.

[00145] In some embodiments, the FEM circuitry 3408 may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include an LNAto amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 3406). The transmit signal path of the FEM circuitry 3408 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 3406), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 3410).

[00146] In some embodiments, the PMC 3412 may manage power provided to the baseband circuitry 3404. In particular, the PMC 3412 may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion. The PMC 3412 may often be included when the device 1100 is capable of being powered by a battery, for example, when the device is included in a UE. The PMC 3412 may increase the power conversion efficiency while providing desirable implementation size and heat dissipation

characteristics.

[00147] While FIG. 34 shows the PMC 3412 coupled only with the baseband circuitry 3404. However, in other embodiments, the PMC 34 35 may be additionally or alternatively coupled with, and perform similar power management operations for, other components such as, but not limited to, application circuitry 3402, RF circuitry 3406, or FEM 3408.

[00148] In some embodiments, the PMC 3412 may control, or otherwise be part of, various power saving mechanisms of the device 1100. For example, if the device 1100 is in an RRC_Connected state, where it is still connected to the RAN node as it expects to receive traffic shortly, then it may enter a state known as Discontinuous Reception Mode (DRX) after a period of inactivity. During this state, the device 1100 may power down for brief intervals of time and thus save power.

[00149] If there is no data traffic activity for an extended period of time, then the device 1100 may transition off to an RRC Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The device 1100 goes into a very low power state and it performs paging where again it periodically wakes up to listen to the network and then powers down again. The device 1100 may not receive data in this state, in order to receive data, it must transition back to RRC Connected state.

[00150] An additional power saving mode may allow a device to be unavailable to the network for periods longer than a paging interval (ranging from seconds to a few hours). During this time, the device is totally unreachable to the network and may power down completely. Any data sent during this time incurs a large delay and it is assumed the delay is acceptable.

[00151] Processors of the application circuitry 3402 and processors of the baseband circuitry 3404 may be used to execute elements of one or more instances of a protocol stack. For example, processors of the baseband circuitry 3404, alone or in combination, may be used execute Layer 3, Layer 2, or Layer 1 functionality, while processors of the application circuitry 3404 may utilize data (e.g., packet data) received from these layers and further execute Layer 4 functionality (e.g., transmission communication protocol (TCP) and user datagram protocol (UDP) layers). As referred to herein, Layer 3 may comprise a radio resource control (RRC) layer, described in further detail below. As referred to herein, Layer 2 may comprise a medium access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer, described in further detail below. As referred to herein, Layer 1 may comprise a physical (PHY) layer of a UE/RAN node, described in further detail below. [00152] FIG. 35 illustrates example interfaces of baseband circuitry in accordance with some embodiments. As discussed above, the baseband circuitry 3404 of FIG. 34 may comprise processors 3404a-3404e and a memory 3404g utilized by said processors. Each of the processors 3404a-3404e may include a memory interface, 3504a-3504e, respectively, to send/receive data to/from the memory 3404g.

[00153] The baseband circuitry 3404 may further include one or more interfaces to communicatively couple to other circuitries/devices, such as a memory interface 3512 (e.g., an interface to send/receive data to/from memory external to the baseband circuitry 3404), an application circuitry interface 3514 (e.g., an interface to send/receive data to/from the application circuitry 3402 of FIG. 34), an RF circuitry interface 3516 (e.g., an interface to send/receive data to/from RF circuitry 3406 of FIG. 34), a wireless hardware connectivity interface 3518 (e.g., an interface to send/receive data to/from Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components), and a power management interface 3520 (e.g., an interface to send/receive power or control signals to/from the PMC 3412.

[00154] FIG. 36 provides an example illustration of the wireless device, such as a user equipment (UE), a mobile station (MS), a mobile wireless device, a mobile communication device, a tablet, a handset, or other type of wireless device. The wireless device can include one or more antennas configured to communicate with a node, macro node, low power node (LPN), or, transmission station, such as a base station (BS), an evolved Node B (eNB), a baseband processing unit (BBU), a remote radio head (RRH), a remote radio equipment (RRE), a relay station (RS), a radio equipment (RE), or other type of wireless wide area network (WWAN) access point. The wireless device can be configured to communicate using at least one wireless communication standard such as, but not limited to, 3 GPP LTE, WiMAX, High Speed Packet Access (HSPA), Bluetooth, and WiFi. The wireless device can communicate using separate antennas for each wireless communication standard or shared antennas for multiple wireless communication standards. The wireless device can communicate in a wireless local area network (WLAN), a wireless personal area network (WPAN), and/or a WWAN. The wireless device can also comprise a wireless modem. The wireless modem can comprise, for example, a wireless radio transceiver and baseband circuitry (e.g., a baseband processor). The wireless modem can, in one example, modulate signals that the wireless device transmits via the one or more antennas and demodulate signals that the wireless device receives via the one or more antennas. [00155] FIG. 36 also provides an illustration of a microphone and one or more speakers that can be used for audio input and output from the wireless device. The display screen can be a liquid crystal display (LCD) screen, or other type of display screen such as an organic light emitting diode (OLED) display. The display screen can be configured as a touch screen. The touch screen can use capacitive, resistive, or another type of touch screen technology. An application processor and a graphics processor can be coupled to internal memory to provide processing and display capabilities. Anon-volatile memory port can also be used to provide data input/output options to a user. The non-volatile memory port can also be used to expand the memory capabilities of the wireless device. A keyboard can be integrated with the wireless device or wirelessly connected to the wireless device to provide additional user input. A virtual keyboard can also be provided using the touch screen.

Examples

[00156] The following examples pertain to specific technology embodiments and point out specific features, elements, or actions that can be used or otherwise combined in achieving such embodiments.

[00157] Example 1 includes an apparatus of a user equipment (UE) operable to generate a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR), the apparatus comprising: one or more processors configured to: generate, at the UE, a binary DM-RS sequence in a time domain; map, at the UE, the binary DM-RS sequence to a pi/2 binary phase shift keying (BPSK) constellation to form a pi/2 BPSK modulated binary DM-RS sequence; perform, at the UE, Discrete Fourier Transform (DFT) spreading and Orthogonal Frequency Division Multiplexing (OFDM) symbol generation on the pi/2 BPSK modulated binary DM-RS sequence to produce the DM-RS having the reduced PAPR; and encode, at the UE, the DM-RS having the reduced PAPR for transmission to a Next Generation NodeB (gNB) on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH); and a memory interface configured to send to a memory the binary DM-RS sequence.

[00158] Example 2 includes the apparatus of Example 1, further comprising a transceiver configured to transmit the DM-RS to the gNB.

[00159] Example 3 includes the apparatus of any of Examples 1 to 2, wherein the DM- RS is Type 1 DM-RS for the PUSCH, or the DM-RS is for PUCCH format 3 and 4 with no comb structure.

[00160] Example 4 includes the apparatus of any of Examples 1 to 3, wherein the one or more processors are configured to use computer generated sequences for generation of the DM-RS for resource allocations up to four physical resource blocks (PRBs) for the PUSCH, corresponding to sequences of length 6,12,18,24 and for the PUCCH

corresponding to up to two PRB allocations with sequence lengths 12, 24.

[00161] Example 5 includes the apparatus of any of Examples 1 to 4, wherein the one or more processors are configured to use pseudo noise (PN) sequences for generation of the DM-RS for the PUSCH with greater than four PRB allocations and the PUCCH with greater than two PRB allocations.

[00162] Example 6 includes the apparatus of any of Examples 1 to 5, wherein the one or more processors are configured to use computer generated sequences for generation of the DM-RS using one or more metrics, wherein the metrics are related to one or more of: minimizing a frequency domain (FD) PAPR (FD-PAPR), minimizing an FD maximum to n-th minimum power ratio with n=l,2,3, 4, 5 or maximizing a P-th percentile FD-power where P=l0,20,30,40,50.

[00163] Example 7 includes the apparatus of any of Examples 1 to 6, wherein the one or more processors are configured to use sequences for generation of the DM-RS which are generated using extended or truncated binary Golay sequences.

[00164] Example 8 includes the apparatus of any of Examples 1 to 7, wherein the one or more processors are configured to generate additional sequences for the DM-RS having the reduced PAPR using one or more of: frequency domain (FD) or time domain (TD) cyclic shifts or TD or FD orthogonal cover codes.

[00165] Example 9 includes the apparatus of any of Examples 1 to 8, wherein the one or more processors are configured to generate the DM-RS having the reduced PAPR using one or more complementary sequences wherein the complementary sequence(s) are mapped to one or more time domain DM-RS symbols.

[00166] Example 10 includes the apparatus of any of Examples 1 to 9, wherein the one or more processors are configured to use non-pi/2 BPSK modulated sequences to generate the DM-RS having the reduced PAPR, wherein the non-pi/2 BPSK modulated sequences include sequences differentially modulated with M-phase shift keying (PSK).

[00167] Example 11 includes the apparatus of any of Examples 1 to 10, wherein the one or more processors are configured to use non-pi/2 BPSK modulated sequences to generate the DM-RS having the reduced PAPR, wherein the non-pi/2 BPSK modulated sequences include sequences using pi/M modulation of M-PSK sequences where M = 4,8 or 16 to optimize a PAPR of OFDM symbol and a frequency domain power spectrum of the generated DM-RS sequence.

[00168] Example 12 includes an apparatus of a user equipment (UE) operable to generate a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR), the apparatus comprising: one or more processors configured to: generate, at the UE, a binary DM-RS sequence in a time domain; apply, at the UE, a pi/2 binary phase shift keying (BPSK) modulation and a Discrete Fourier Transform (DFT) spread Orthogonal Frequency Division Multiplexing (OFDM) waveform or transform precoding on the binary DM-RS sequence to produce the DM-RS having the reduced PAPR; and encode, at the UE, the DM-RS having the reduced PAPR for transmission to a Next Generation NodeB (gNB) on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH); and a memory interface configured to send to a memory the binary DM-RS sequence.

[00169] Example 13 includes the apparatus of Example 12, wherein the DM-RS is Type 1 DM-RS for the PUSCH, or the DM-RS is for PUCCH format 3 and 4 with no comb structure.

[00170] Example 14 includes the apparatus of any of Examples 12 to 13, wherein the one or more processors are configured to use computer generated sequences for generation of the DM-RS for resource allocations up to four physical resource blocks (PRBs) for the PUSCH, corresponding to sequences of length 6,12,18,24 and for the PUCCH corresponding to up to two PRB allocations with sequence lengths 12, 24.

[00171] Example 15 includes the apparatus of any of Examples 12 to 14, wherein the one or more processors are configured to use pseudo noise (PN) sequences for generation of the DM-RS for the PUSCH with greater than four PRB allocations and the PUCCH with greater than two PRB allocations. [00172] Example 16 includes the apparatus of any of Examples 12 to 15, wherein the one or more processors are configured to use computer generated sequences for generation of the DM-RS using one or more metrics, wherein the metrics are related to one or more of: minimizing a frequency domain PAPR (FD-PAPR), minimizing an FD maximum to n-th minimum power ratio with n=l,2,3,4,5, or maximizing a P-th percentile FD-power where P=l 0,20,30,40,50.

[00173] Example 17 includes the apparatus of any of Examples 12 to 16, wherein the one or more processors are configured to generate additional sequences for the DM-RS having the reduced PAPR using frequency domain (FD) or time domain (TD) cyclic shifts.

[00174] Example 18 includes the apparatus of any of Examples 12 to 17, wherein the one or more processors are configured to generate the DM-RS having the reduced PAPR using one or more complementary sequences.

[00175] Example 19 includes the apparatus of any of Examples 12 to 18, wherein the one or more processors are configured to use non-pi/2 BPSK modulated sequences to generate the DM-RS having the reduced PAPR, wherein the non-pi/2 BPSK modulated sequences include sequences differentially modulated with M-phase shift keying (PSK).

[00176] Example 20 includes at least one machine readable storage medium having instructions embodied thereon for generating a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR), the instructions when executed by one or more processors at a user equipment (UE) perform the following: generating, at the UE, a binary DM-RS sequence in a time domain; mapping, at the UE, the binary DM- RS sequence to a pi/2 binary phase shift keying (BPSK) constellation to form a pi/2 BPSK modulated binary DM-RS sequence; performing, at the UE, Discrete Fourier Transform (DFT) spreading and Orthogonal Frequency Division Multiplexing (OFDM) symbol generation on the pi/2 BPSK modulated binary DM-RS sequence to produce the DM-RS having the reduced PAPR; and encoding, at the UE, the DM-RS having the reduced PAPR for transmission to a Next Generation NodeB (gNB) on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH).

[00177] Example 21 includes the at least one machine readable storage medium of Example 20, wherein the DM-RS is Type 1 DM-RS for the PUSCH, or the DM-RS is for PUCCH format 3 and 4 with no comb structure.

[00178] Example 22 includes the at least one machine readable storage medium of any of Examples 20 to 21, further comprising instructions when executed perform the following: using computer generated sequences for generation of the DM-RS for resource allocations up to four physical resource blocks (PRBs) for the PUSCH, corresponding to sequences of length 6,12,18,24 and for the PUCCH corresponding to up to two PRB allocations with sequence lengths 12, 24.

[00179] Example 23 includes the at least one machine readable storage medium of any of Examples 20 to 22, further comprising instructions when executed perform the following: using pseudo noise (PN) sequences for generation of the DM-RS for the PUSCH with greater than four PRB allocations and the PUCCH with greater than two PRB allocations.

[00180] Example 24 includes the at least one machine readable storage medium of any of Examples 20 to 23, further comprising instructions when executed perform the following: generating additional sequences for the DM-RS having the reduced PAPR using frequency domain (FD) or time domain (TD) cyclic shifts.

[00181] Example 25 includes the at least one machine readable storage medium of any of Examples 20 to 24, further comprising instructions when executed perform the following: using non-pi/2 BPSK modulated sequences to generate the DM-RS having the reduced PAPR, wherein the non-pi/2 BPSK modulated sequences include sequences differentially modulated with M-phase shift keying (PSK).

[00182] Various techniques, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, compact disc-read-only memory (CD-ROMs), hard drives, non-transitory computer readable storage medium, or any other machine-readable storage medium wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the various techniques. In the case of program code execution on programmable computers, the computing device may include a processor, a storage medium readable by the processor (including volatile and non volatile memory and/or storage elements), at least one input device, and at least one output device. The volatile and non-volatile memory and/or storage elements may be a random-access memory (RAM), erasable programmable read only memory (EPROM), flash drive, optical drive, magnetic hard drive, solid state drive, or other medium for storing electronic data. The node and wireless device may also include a transceiver module (i.e., transceiver), a counter module (i.e., counter), a processing module (i.e., processor), and/or a clock module (i.e., clock) or timer module (i.e., timer). In one example, selected components of the transceiver module can be located in a cloud radio access network (C-RAN). One or more programs that may implement or utilize the various techniques described herein may use an application programming interface (API), reusable controls, and the like. Such programs may be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program(s) may be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language, and combined with hardware implementations.

[00183] As used herein, the term "circuitry" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, circuitry may include logic, at least partially operable in hardware.

[00184] It should be understood that many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom very-large-scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

[00185] Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions, which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module may not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.

[00186] Indeed, a module of executable code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network. The modules may be passive or active, including agents operable to perform desired functions.

[00187] Reference throughout this specification to "an example" or“exemplary” means that a particular feature, structure, or characteristic described in connection with the example is included in at least one embodiment of the present technology. Thus, appearances of the phrases "in an example" or the word“exemplary” in various places throughout this specification are not necessarily all referring to the same embodiment.

[00188] As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example of the present technology may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as defacto equivalents of one another, but are to be considered as separate and autonomous representations of the present technology.

[00189] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of layouts, distances, network examples, etc., to provide a thorough understanding of embodiments of the technology. One skilled in the relevant art will recognize, however, that the technology can be practiced without one or more of the specific details, or with other methods, components, layouts, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the technology.

[00190] While the forgoing examples are illustrative of the principles of the present technology in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the technology.

Claims

CLAIMS What is claimed is:

1. An apparatus of a user equipment (UE) operable to generate a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR), the apparatus comprising:

one or more processors configured to:

generate, at the UE, a binary DM-RS sequence in a time domain;

map, at the UE, the binary DM-RS sequence to a pi/2 binary phase shift keying (BPSK) constellation to form a pi/2 BPSK modulated binary DM-RS sequence;

perform, at the UE, Discrete Fourier Transform (DFT) spreading and Orthogonal Frequency Division Multiplexing (OFDM) symbol generation on the pi/2 BPSK modulated binary DM-RS sequence to produce the DM-RS having the reduced PAPR; and

encode, at the UE, the DM-RS having the reduced PAPR for transmission to a Next Generation NodeB (gNB) on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH); and

a memory interface configured to send to a memory the binary DM-RS sequence.

2. The apparatus of claim 1, further comprising a transceiver configured to

transmit the DM-RS to the gNB.

3. The apparatus of claim 1, wherein the DM-RS is Type 1 DM-RS for the

PUSCH, or the DM-RS is for PUCCH format 3 and 4 with no comb structure.

4. The apparatus of claim 1, wherein the one or more processors are configured to use computer generated sequences for generation of the DM-RS for resource allocations up to four physical resource blocks (PRBs) for the PUSCH, corresponding to sequences of length 6,12,18,24 and for the PUCCH corresponding to up to two PRB allocations with sequence lengths 12, 24.

5. The apparatus of any of claims 1 to 4, wherein the one or more processors are configured to use pseudo noise (PN) sequences for generation of the DM-RS for the PUSCH with greater than four PRB allocations and the PUCCH with greater than two PRB allocations.

6. The apparatus of any of claims 1 to 4, wherein the one or more processors are configured to use computer generated sequences for generation of the DM-RS using one or more metrics, wherein the metrics are related to one or more of: minimizing a frequency domain (FD) PAPR (FD-PAPR), minimizing an FD maximum to n-th minimum power ratio with n=l,2,3, 4, 5 or maximizing a P- th percentile FD-power where P=l0,20,30,40,50.

7. The apparatus of any of claims 1 to 4, wherein the one or more processors are configured to use sequences for generation of the DM-RS which are generated using extended or truncated binary Golay sequences.

8. The apparatus of any of claims 1 to 4, wherein the one or more processors are configured to generate additional sequences for the DM-RS having the reduced PAPR using one or more of: frequency domain (FD) or time domain (TD) cyclic shifts or TD or FD orthogonal cover codes.

9. The apparatus of any of claims 1 to 4, wherein the one or more processors are configured to generate the DM-RS having the reduced PAPR using one or more complementary sequences wherein the complementary sequence(s) are mapped to one or more time domain DM-RS symbols.

10. The apparatus of any of claims 1 to 4, wherein the one or more processors are configured to use non-pi/2 BPSK modulated sequences to generate the DM- RS having the reduced PAPR, wherein the non-pi/2 BPSK modulated sequences include sequences differentially modulated with M-phase shift keying (PSK).

11. The apparatus of any of claims 1 to 4, wherein the one or more processors are configured to use non-pi/2 BPSK modulated sequences to generate the DM- RS having the reduced PAPR, wherein the non-pi/2 BPSK modulated sequences include sequences using pi/M modulation of M-PSK sequences where M = 4,8 or 16 to optimize a PAPR of OFDM symbol and a frequency domain power spectrum of the generated DM-RS sequence.

12. An apparatus of a user equipment (UE) operable to generate a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR), the apparatus comprising:

one or more processors configured to:

generate, at the UE, a binary DM-RS sequence in a time domain; apply, at the UE, a pi/2 binary phase shift keying (BPSK) modulation and a Discrete Fourier Transform (DFT) spread Orthogonal Frequency Division Multiplexing (OFDM) waveform or transform precoding on the binary DM- RS sequence to produce the DM-RS having the reduced PAPR; and

a memory interface configured to send to a memory the binary DM-RS sequence.

13. The apparatus of claim 12, wherein the DM-RS is Type 1 DM-RS for the PUSCH, or the DM-RS is for PUCCH format 3 and 4 with no comb structure.

14. The apparatus of claim 12, wherein the one or more processors are configured to use computer generated sequences for generation of the DM-RS for resource allocations up to four physical resource blocks (PRBs) for the PUSCH, corresponding to sequences of length 6,12,18,24 and for the PUCCH corresponding to up to two PRB allocations with sequence lengths 12, 24.

15. The apparatus of claim 12, wherein the one or more processors are configured to use pseudo noise (PN) sequences for generation of the DM-RS for the PUSCH with greater than four PRB allocations and the PUCCH with greater than two PRB allocations.

16. The apparatus of any of claims 12 to 15, wherein the one or more processors are configured to use computer generated sequences for generation of the DM- RS using one or more metrics, wherein the metrics are related to one or more of: minimizing a frequency domain PAPR (FD-PAPR), minimizing an FD maximum to n-th minimum power ratio with n=l,2,3,4,5, or maximizing a P- th percentile FD-power where P=l0,20,30,40,50.

17. The apparatus of any of claims 12 to 15, wherein the one or more processors are configured to generate additional sequences for the DM-RS having the reduced PAPR using frequency domain (FD) or time domain (TD) cyclic shifts.

18. The apparatus of any of claims 12 to 15, wherein the one or more processors are configured to generate the DM-RS having the reduced PAPR using one or more complementary sequences.

19. The apparatus of claim 12, wherein the one or more processors are configured to use non-pi/2 BPSK modulated sequences to generate the DM-RS having the reduced PAPR, wherein the non-pi/2 BPSK modulated sequences include sequences differentially modulated with M-phase shift keying (PSK).

20. At least one machine readable storage medium having instructions embodied thereon for generating a demodulation reference signal (DM-RS) having a reduced peak-to-average power ratio (PAPR), the instructions when executed by one or more processors at a user equipment (UE) perform the following: generating, at the UE, a binary DM-RS sequence in a time domain; mapping, at the UE, the binary DM-RS sequence to a pi/2 binary phase shift keying (BPSK) constellation to form a pi/2 BPSK modulated binary DM- RS sequence;

performing, at the UE, Discrete Fourier Transform (DFT) spreading and Orthogonal Frequency Division Multiplexing (OFDM) symbol generation on the pi/2 BPSK modulated binary DM-RS sequence to produce the DM-RS having the reduced PAPR; and

encoding, at the UE, the DM-RS having the reduced PAPR for transmission to a Next Generation NodeB (gNB) on a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH).

21. The at least one machine readable storage medium of claim 20, wherein the DM-RS is Type 1 DM-RS for the PUSCH, or the DM-RS is for PUCCH format 3 and 4 with no comb structure.

22. The at least one machine readable storage medium of claim 20, further

comprising instructions when executed perform the following: using computer generated sequences for generation of the DM-RS for resource allocations up to four physical resource blocks (PRBs) for the PUSCH, corresponding to sequences of length 6,12,18,24 and for the PUCCH corresponding to up to two PRB allocations with sequence lengths 12, 24.

23. The at least one machine readable storage medium of claim 20, further

comprising instructions when executed perform the following: using pseudo noise (PN) sequences for generation of the DM-RS for the PUSCH with greater than four PRB allocations and the PUCCH with greater than two PRB allocations.

24. The at least one machine readable storage medium of any of claims 20 to 23, further comprising instructions when executed perform the following:

generating additional sequences for the DM-RS having the reduced PAPR using frequency domain (FD) or time domain (TD) cyclic shifts.

25. The at least one machine readable storage medium of claim 20, further comprising instructions when executed perform the following: using non-pi/2 BPSK modulated sequences to generate the DM-RS having the reduced PAPR, wherein the non-pi/2 BPSK modulated sequences include sequences differentially modulated with M-phase shift keying (PSK).