CN110858788A

CN110858788A - Data symbol configuration method

Info

Publication number: CN110858788A
Application number: CN201810890300.XA
Authority: CN
Inventors: 黎光洁; 王明威; 李春宏; 吴冶
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-08-07
Filing date: 2018-08-07
Publication date: 2020-03-03
Anticipated expiration: 2038-08-07
Also published as: CN110858788B

Abstract

The invention discloses a configuration method of data symbols in a communication frame structure, and relates to the field of communication. The data symbol is a data transmission unit and consists of PCP control and data; the PCP is controlled to be a PCP sequence and is obtained through a corresponding generation method. For uplink and downlink common control channels, the PCP sequences are generated by corresponding PCP generators; when the uplink common control channel carries non-ACK information or the uplink shared data channel carries short messages, one of the C-PCP sequences is selected as a PCP sequence randomly or in a designated mode. By adopting the technical scheme, the method can be used for predefining different sequence lengths on different channels to improve the efficiency of the whole system, and the combination with the receiver can ensure that the signal-to-noise ratio of signals received by the communication system can be as low as-30 dB, so that the WIoTa terminal can still work under some extreme conditions, and meanwhile, the base station can also cover a large range, thereby reducing the deployment and maintenance cost of the system, greatly reducing the complexity of the terminal and improving the air interface efficiency.

Description

Data symbol configuration method

Technical Field

The invention relates to the field of communication, in particular to a configuration method of data symbols in a communication frame structure.

Background

The IoT of the Internet of things must replace the smart phone to become the next powerful growing point of the information industry, and the output value of the IoT is generally considered to reach the level of 5 to 10 times that of the smart phone. Meanwhile, the IoT and artificial intelligence technology are two key technologies which supplement each other in the future high technology, and in the process of steady increase, the outbreak time point is brought. Artificial intelligence solves the problem of intelligent computing, while IoT solves the problem of seamless networking. The two are indispensable to each other. The IoT internet of things has a blowout situation in the aspect of short-distance application, and the main reason is the rise of smart homes, and meanwhile, as a main communication technology, WIFI is complete in infrastructure (each home has a WIFI access point). In the aspect of wide-area internet of things with high additional value, in the accumulation stage, each communication standard is available in the ink, and the infrastructure, low-cost and low-power consumption chips have not made substantial breakthrough.

In the prior art, in order to overcome intersymbol interference ISI (inter-symbol interference) peculiar to an OFDM (orthogonal frequency division multiplexing) system, the LTE introduces a concept of cyclic prefix, adopts initial synchronization based on CP (content provider), and has an algorithm only based on a differential method, and can work only when the signal-to-noise ratio of a received signal is required to be higher than about-10 dB, so that a communication terminal of the LTE can not normally work in some poor environments or conditions, the coverage range of a base station is small, and the system deployment and maintenance cost is too high.

Disclosure of Invention

The invention aims to: in view of the above existing problems, a method for configuring data symbols in a communication frame is provided, which is used to predefine different sequences on different channels to improve the efficiency of the whole communication system.

The technical scheme adopted by the invention is as follows:

a configuration method of data symbols is provided, the data symbols are a data transmission unit and are formed by PCP control and data; the PCP is controlled to be a PCP sequence and is obtained through a corresponding generation method.

The PCP refers to a cyclic prefix with a predefined variable length, and the maximum length of the PCP sequence is 1/2 of the length of the data symbol.

In one data symbol, when the PCP control and data are out of phase, corresponding 0 is filled before and after the data as a modulation symbol.

The modulation scheme of the PCP is one of 1/2Pi BPSK, 1/4Pi BPSK, and 1/8Pi BPSK.

For uplink and downlink common control channels, the PCP sequences are generated by corresponding PCP generators; when the uplink common control channel carries non-ACK information or the uplink shared data channel carries short messages, one of the C-PCP sequences is selected as a PCP sequence randomly or in a designated mode.

The method of generating a PCP sequence by a corresponding PCP generator is as follows:

setting the number of PCP sampling points to be generated as n _ PCP, and firstly generating a random sequence flow by a random number sequence generator;

secondly, generating a random phase, and modulating the obtained random sequence flow to obtain n _ PCP random modulation symbols as PCP.

The input parameters of the random number sequence generator are as follows:

GOLDEN_X1_INIT(0:47)＝mod(SUBSYSTEM_ID+Param_0,2),GOLDEN_X1_INIT(49)＝0；

GOLDEN_X2_INIT(0:47)＝mod(USER_ID_SCRAMBLED+Param_1,2),GOLDEN_X2_INIT(49)＝0；

the USER _ ID _ scramblled is an ID obtained by scrambling a network USER ID/device ID, the Param _0 and Param _1 parameters are system initialization parameters, and values of the parameters are set differently according to different physical layer channels.

The generation method of the C-PCP sequence set comprises the following steps:

the input parameters are: the number of sequences n _ set, and the length of the sequences n _ length;

step 1, using a PCP generator to generate a PCP sequence with the length of n _ set x n _ length;

and 2, equally dividing the generated sequences with the length of n _ set x n _ length into n _ set parts to obtain a set of n _ set sequences, namely the C-PCP sequence set.

After a PCP sequence with a certain length is generated by the PCP generation method, the PCP sequence is used as control and data to form a data symbol, so that the communication process is completed.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. according to the embodiment provided by the invention, a parameter PCP (variably predefined CP) is introduced into a communication frame structure, the parameter PCP can be used for predefining different sequences on different channels to improve the efficiency of the whole system, and the signal-to-noise ratio of a received signal of the communication system can be as low as-30 dB by combining with a receiver, so that a terminal of WIoTa can still work under some extreme conditions, and meanwhile, a base station can also cover a large range, thereby reducing the deployment and maintenance cost of the system.

2. According to the embodiments provided by the invention, the channel estimation, synchronization, SINR detection and the like can be realized by using the PCP, so that the complexity of the terminal can be greatly reduced, the air interface efficiency can be improved, and meanwhile, the PCP can also be used for tracking processing and channel estimation during data receiving, thereby realizing one signal and multiple purposes and improving the spectrum efficiency of the whole system.

Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

fig. 1 is a schematic diagram of a basic frame structure provided in this embodiment.

Fig. 2 is a schematic structural diagram of the data symbol provided in this embodiment.

Detailed Description

In order to make the technical solutions of the present invention better understood, the following description of the technical solutions of the present invention with reference to the accompanying drawings of the present invention is made clearly and completely, and other similar embodiments obtained by a person of ordinary skill in the art without any creative effort based on the embodiments in the present application shall fall within the protection scope of the present application.

In this embodiment, a basic frame in internet Of Things communication based on a WIoTa (Wide-range internet Of Things communications protocol) protocol is described, where the basic frame structure is an elastic frame structure and a description Of a corresponding basic frame configuration method, and these descriptions may be applied to other mobile communication systems.

It should be noted that, in a mobile communication system, a user equipment may receive information from a base station in a downlink and transmit information to the base station in an uplink. The information transmitted or received by the user equipment may include data and various control information. And various types of physical channels may exist according to the type and use of information transmitted or received by the user equipment.

The configuration method and embodiments of the present invention can be applied to various wireless access systems, including CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access), and the like.

The meaning of the individual parameters which are to be found in the following examples is first explained:

data symbol: the data symbol represents a communication data transmission unit, consists of PCP control and data, and the number of Ts points is the power of 2;

frame: a frame consisting of 16 subframes, each subframe starting with a broadcast channel broadcast frame number;

subframe: a subframe, which may be uplink or downlink;

burst: one Burst is the minimum transmission unit, one or more subframes can be occupied according to the difference of the BOOST Level, and one basic transmission unit is fixedly composed of 8 time slots (slots);

slot: and one time slot is a unit occupied by the PD-CCCH and PU-CCCH physical layer channels.

The level of the coverage capacity is increased, the higher the level is, the more occupied air interface resources (the more data repetition) is, and the stronger the coverage capacity (BOOST) is;

AP is access point;

DL/UL ratio: the uplink and downlink ratio, when the DL/UL ratio is 1, the frame structure is a basic frame, otherwise, the frame structure is an extended frame;

cyclic-redundancy check (CRC);

PCP (primary phenol treatment): variable predefined CP refers to a cyclic prefix of a predefined variable length.

PPS: predefined pilot sequence refers to a predefined pilot sequence.

Repetition Group: the repetition group parameter RG refers to basic data symbols to be occupied by information bits (bits), and if a basic transmission unit contains more symbols, repetition is performed by taking RG as a unit. The common control channel fixedly uses RG of 1, and the data channel can use a large RG.

The WIoTa communication system employs TDD time division duplex mode, one frame is fixed to 34.133/2ms, one subframe contains one Rx and one Tx (equal in time), and 8 subframes are one frame.

In addition, a coverage capability parameter BOOST is defined in the WIoTa protocol, and the introduction of the BOOST parameter can lead different users to adopt different BOOST values according to different channel conditions, thereby controlling the modulation coding and the repetition times of the channel and the data channel to be controlled by the BOOST at the same time. Therefore, the system efficiency can be greatly improved, users with good channel conditions occupy less system resources, and basic communication requirements for users with poor channel conditions are considered.

Different user channel conditions correspond to different BOOST levels, which indicate the coverage capacity improvement level, and the higher the coverage capacity is, the more occupied air interface resources (the more data repetition is), and the stronger the coverage capacity is. Different coverage capacity promotion levels correspond to different values of the coverage capacity parameter BOOST, and the basic frame structure can be configured through the configuration of the BOOST.

The ability to adapt to different channel conditions can be provided in the network when the overlay capability parameter (BOOST) is configured to different values. For example, when the BOOST is 0, a slot contains 8 data symbols. And when the BOOST is 1, a slot contains 16 data symbols l, and one data symbol is 512 sampling points (corresponding to a system with a bandwidth of 2 MHz), which can support a larger coverage. When the BOOST is-1, a slot contains 4 data symbols, and the coverage is smaller but the transmission capacity is larger.

It should be noted that, for the configurable parameters in the following embodiments, corresponding settings may be performed according to conditions such as a network application scenario and a scale when a network is built or deployed, for example, an uplink-downlink ratio in a frame structure, a coverage capability parameter BOOST, and the like. The set network can be used for realizing effective communication of the data of the Internet of things according to the configuration parameters.

Example 1

Fig. 1 shows a basic frame structure under the condition that the bandwidth of 1.25MHz (the sampling rate of 1.92MHz, the sampling interval is 0.5208us) and the coverage capability parameter BOOST is configured to be 0.

As shown in fig. 1, one frame (frame) is 273.0668 ms, and includes 16 subframes (subframes), and the ratio of DL/UL ratio is set to be 1: 1, the uplink and downlink subframes are arranged in a staggered manner.

The basic/minimum transmission unit of user data is one basic transmission unit. A basic transmission unit is fixed to contain 8 slots. As shown in fig. 1, when the BOOST configuration is 0, a slot includes 8 data symbols, one data symbol is a basic transmission unit, and includes control and data therein, and 8 slots constitute a basic transmission unit. Here, one downlink data symbol is 512Ts, and the number of sampling points of the uplink data symbol may be configured accordingly according to specific network requirements (512 points, 256 points, 128 points, 64 points).

In this embodiment, the uplink and the downlink are arranged in a staggered manner, each of the uplink basic transmission unit and the downlink basic transmission unit corresponds to one uplink subframe and one downlink subframe respectively, the IoT terminal device accesses the internet of things communication network under the configuration condition of the coverage capability parameter BOOST, and the corresponding access point also performs data transmission with each terminal device under the same BOOST configuration condition.

Example 2

In this embodiment, a detailed description is further given of a corresponding basic frame structure when data symbols based on the PCP are configured differently.

As can be seen from example 1, the Data symbol (Data symbol) is a Data transmission unit of WIoTa communication, is composed of PCP control plus Data, and is also a PCP sequence, as shown in fig. 2. Wherein the pcp (variable predefinadcp) refers to a predefined cyclic prefix of variable length. For the PCP control, the sequence is of a certain length and is obtained by a certain generation method. For one data symbol, the length of the PCP sequence is at its maximum 1/2 times the length of the data symbol.

In order to overcome intersymbol interference ISI (inter-symbol interference) specific to an OFDM (orthogonal frequency division multiplexing) system, the LTE introduces a cyclic prefix concept, and adopts initial synchronization based on CP (cyclic content provider), and an algorithm of the LTE can only be based on a differential method and can work when the signal-to-noise ratio of a received signal is higher than about-10 dB. Unlike CP in LTE, the PCP defined in this embodiment improves the efficiency of the whole system by predefining sequence prefixes of different lengths on different channels. In one embodiment, the PCP in combination with the receiver algorithm can achieve time and frequency synchronization of the receiver and the transmitter in a shorter time, thereby greatly reducing power consumption and cost of the chip. In another embodiment, the PCP can be used for tracking processing and channel estimation during data reception, thereby realizing multiple purposes of one signal and improving the spectrum efficiency of the whole system.

The PCP scheme provided by the embodiment of the invention can adopt a differential algorithm and a related algorithm, so that the signal-to-noise ratio of a received signal can be as low as-30 dB, and thus, the WIoTa-based terminal for the wide area Internet of things communication can still normally work in severe environments or extreme situations, and meanwhile, a base station can also cover a large range, and the deployment and maintenance cost of the system is reduced.

The WIoTa communication system is a CPM (continuous phase modulation) -based basic scheme, and the method can ensure continuous phase and constant modulus modulation and maximally utilize frequency spectrum resources. Because the PCP is fixed and modulated by using a BPSK modulation scheme, including 1/2piBPSK, 1/4pi26QPSK, 1/8pi8PSK, and the data portion may also be 1/2pi BPSK, 1/4pi26QPSK, 1/8pi8PSK, the problem of phase discontinuity is caused. While symbol scrambling by multiplying the +1 and-1 directly on the symbols also has the problem of phase discontinuity.

To solve the above problem, bit 0 needs to be padded in the transmission data part, and the way of padding 0 is as follows:

1) PCP +1/2pi BPSK not filled with 0;

2) PCP +1/4pi QPSK: PCP +000000data 000000 (6 bits before and after each, 3 modulation symbols)

3) PCP +1/8pi 8 PSK: PCP +000000000data 000000000 (9 bits before and after, 3 modulation symbols).

In one embodiment, the uplink PCP and the downlink PCP may use 1/2Pi BPSK random constellation point sequences, and the parameters of the downlink sequence are generated by a SYSTEM ID (SYSTEM _ ID) and a SUBSYSTEM ID (SUBSYSTEM _ ID) configured by the AP. Channel estimation, synchronization, SINR detection, etc. can all be implemented using PCP, which can greatly reduce the complexity of the terminal and improve the air interface efficiency.

Due to the fact that the WIoTa Internet of things communication design can work in various frequency bands, such as 433/470MHz frequency bands in China and 900MHz frequency bands in North America, and specific working frequency bands need to be arranged according to actual conditions. The maximum transmission power is also related to the practical situation of various places, such as 433/470MHz in China, and the transmission power is required to be lower than 50 mw.

And the WIoTa supports the bandwidth of 625KHz,1.25MHz,2.5MHz,5Mhz,10Mhz and the like, and the bandwidth is expanded according to the power of 2, and the corresponding basic sampling frequencies are 960KHz,1.92MHz,3.84MHz,7.68MHz and 15.36 Mhz. The time unit (Ts) of each sampling point corresponds to 1.0417 microseconds, 0.5208 microseconds, 0.2604 microseconds, 0.1302 microseconds and 0.0651 microseconds respectively under different bandwidths. Typical configuration parameters for 1, 2, 4MHz bandwidth systems are described in the following table, and the specific parameter configuration in practical application needs to be determined according to the system requirements.

TABLE 1 basic configuration parameters Table

Example 3

In this embodiment, a method for configuring data symbols based on a PCP is described, since the PCP is a control bit in a data symbol, and the length and specific value of the PCP both affect practical application results such as channel transmission, synchronization, scrambling, and the like, the length and data value of the generated PCP need to be configured.

In this embodiment, the PCPs are generated by corresponding PCP generators, and the PCPs uplink and downlink on the common control channel are composed of 1/2Pi BPSK sequences, so first, the generation method of the PCPs uplink and downlink on the common control channel is described as follows:

setting the number of PCP sampling points to be generated as n _ PCP, firstly generating random bit by a random number sequence generator, inputting parameters:

GOLDEN_X1_INIT(0:47)＝mod(SUBSYSTEM_ID+Param_0,2),GOLDEN_X1_INIT(49)＝0；

the USER _ ID _ scramblled is an ID obtained by scrambling an original USER ID/device ID.

The N _ pep, Param _0, and Param _1 parameters differ at different physical layer channels.

And secondly, generating a random phase, and carrying out 1/2Pi BPSK modulation on the obtained random sequence bit stream to obtain n _ PCP random modulation symbols as PCP.

Wherein the random number sequence generator is preferably a GOLD sequence generator.

When the uplink common control channel carries non-ACK information or the uplink shared data channel carries short messages, one of the C-PCP sequences can be selected to be used as a PCP. The generation method of the sequence set of C-PCP is as follows: inputting parameters: the number of sequences n _ set and the length of the sequences n _ length.

Step 1, using a PCP generator to generate a PCP sequence with a length of n _ set × n _ length, wherein USER _ ID _ SCRAMBLED is set to Param _0 ═ RAND _ UC _ PCP _0, and ramam _1 ═ RAND _ UC _ PCP _ 1.

And 2, equally dividing the generated sequences with the length of n _ SET x n _ length into n _ SET parts to obtain a SET of n _ SET sequences, namely UC _ PCP _ SET.

Wherein n _ SET is determined by a system parameter UC _ PCP _ SET _ SIZE, if n _ SET is small, UC _ PCP _ SET duplication of different systems is easy to occur, and if n _ SET is too large, processing at the AP end is complicated.

Through a certain PCP generation method, a PCP sequence with a certain length is generated and used as control and data to form data symbols, so that the PCP sequence is used for communication processes such as channel estimation, synchronization and the like, and the communication efficiency of the whole communication system is improved.

The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.

Claims

1. A configuration method of data symbols is characterized in that the data symbols are a data transmission unit and are formed by PCP control and data; the PCP is controlled to be a PCP sequence and is obtained through a corresponding generation method.

2. The method of claim 1, wherein the PCP refers to a cyclic prefix of a predefined variable length, and the length of the PCP sequence is 1/2 of the maximum length of the data symbol.

3. The method of claim 2, wherein in one data symbol, when the PCP control and the data have phase discontinuity, corresponding 0 s are filled before and after the data as modulation symbols.

4. The method of claim 2, wherein the PCP is modulated by one of 1/2PiBPSK, 1/4Pi BPSK, and 1/8Pi BPSK.

5. The method of configuring data symbols of claim 2, wherein the PCP sequences are generated by respective PCP generators for uplink and downlink common control channels;

when the uplink common control channel carries non-ACK information or the uplink shared data channel carries short messages, one of the C-PCP sequences is selected as a PCP sequence randomly or in a designated mode.

6. The method of configuring data symbols of claim 5, wherein the PCP sequences are generated by respective PCP generators by:

7. The method of claim 6, wherein the input parameters of the random number sequence generator are:

GOLDEN_X1_INIT(0:47)＝mod(SUBSYSTEM_ID+Param_0,2),GOLDEN_X1_INIT(49)＝0；

8. The method for configuring data symbols according to claim 7, wherein the C-PCP sequence set is generated by:

9. The method of claim 1, wherein the PCP sequence having a certain length is generated by the PCP generation method, and then the data symbol is formed as control and data for completing the communication procedure.