CN101421966A - Pilot modulation error ratio for evaluation of transmitter performance - Google Patents

Abstract

Systems and methodologies are described that facilitate monitoring transmitter performance in a wireless communication environment. A metric or metrics associated with one or more pilot symbols can be generated and used to evaluate performance. To generate pilot metrics, a signal analyzer can be used to sample the output of a transmitter and the sampled signal can be propagated to a processor. The processor can generate frequency domain channel estimates for subcarriers. Average channel estimates for the subcarriers can be used with the known pilot symbols to determine noise or error for each subcarrier, which can be used to generate the noise variance for each of the pilot symbols. A pilot modulation error metric can be generated based upon the average channel estimates and noise variance.

Description

The pilot modulation error ratio that is used for evaluation of transmitter performance

Cross reference

The application requires to be filed in the U.S. Provisional Application S/N.60/791 that is entitled as " PILOT MODULATIONERROR RATE (pilot modulation error rate) " that submitted on April 12nd, 2006,753 rights and interests.All contents of the application of above institute reference are included in this by reference.

Background

I. field

Below describe and relate generally to radio communication, relate in particular to the evaluation of transmitter performance.

II. background

Wireless networking system has become the means in vogue that most of in the world people are communicated by letter by this.Wireless Telecom Equipment has become more and more littler and has satisfied consumer's needs and improve portability and convenience scheming from strength to strength.The consumer has become and has relied on the Wireless Telecom Equipment that requires reliability services and expanded areas of coverage such as cell phone, PDA(Personal Digital Assistant) etc.

Typical cordless communication network (for example, adopting frequency division, time-division and sign indicating number branch technology) comprise one or more than base station and one or above mobile (for example, wireless) subscriber equipment that can transmit and receive data in the overlay area of overlay area are provided.Typical base station can be transmitted a plurality of data flow that belong to broadcasting, multicast and/or unicast service simultaneously, and wherein data flow is that subscriber equipment is had the independent stream that receives the data of meaning.Drop on subscriber equipment in the overlay area of this base station have interest receive combined-flow entrained, more than one or all data flow.Similarly, a subscriber equipment can transmit data to base station or another subscriber equipment.

Only forward link (FLO) technology is developed the latest developments that utilize system design by wireless communication service provider industry colony and is realized the first water performance.The FLO technology is intended to be used for the mobile multimedia environment and is suitable for using together in conjunction with mobile subscriber equipment.The FLO technology is designed to both receive for other data, services realizes high-quality for real time content stream send also.The FLO technology can provide sane travelling performance and high power capacity and can not bring disaster to power consumption.In addition, this technology reduces the network cost of sending content of multimedia by the number that reduces the base station transmitter that needs deployment.In addition, be complementary based on the multi-medium multi-packet broadcasting of FLO technology and the cellular network data and the voice service of cellular carrier, they are delivered to identical mobile device with content.

The base station transmitter performance is vital for the overall performance of wireless system.Error in the signal that transmitter generates or noise may cause loss of data between transmitter and the receiver or impaired.Especially, in utilizing the FLO technology wireless system of---it may utilize less transmitter---, the performance of each transmitter is very crucial.

Summary

Below provide simplification general introduction to one or above embodiment to scheme to provide basic comprehension to embodiment like this.Detailed the combining of the not all embodiment that contemplates of this summary look at, and neither is intended to point out out the also non-scope of attempting to define any or all embodiment of key or decisive key element of all embodiment.Its unique purpose is the preface that some notions that will provide or above embodiment are in simplified form thought the specific description more that provides after a while.

According to one or above embodiment and corresponding open, the various aspects that are associated with transmitter performance in the monitoring wireless communication environment have been described.One or more that are associated with one or above pilot frequency code element are measured and can be generated and be used for assess performance.Measure in order to generate pilot tone, signal analyzer can be used to sample output and this sampled signal of transmitter can be transmitted to processor.Processor can generate the frequency domain channel of all subcarriers and estimate.The average channel estimation of these subcarriers can be used for determining the noise or the error of each subcarrier with known pilot symbols, and it can be used to generate in these pilot frequency code elements the noise variance of each.Pilot modulation error is measured and can be generated based on average channel estimation and noise variance.

On the one hand, a kind of method comprises: generate the average frequency domain channel estimating of each subcarrier on the unit data of transmitter signal; The pilot frequency code element noise of each that determine based on each the average frequency domain channel estimating in these subcarriers to be associated with pilot frequency code element in these subcarriers.This method comprises at least in part the average noise variance of determining this pilot frequency code element based on the pilot frequency code element noise of each that is associated with this pilot frequency code element in these subcarriers subsequently.This method comprises at least in part the pilot modulation error ratio that generates the indication transmitter performance based on the average frequency domain channel estimating of each in the average noise variance of this pilot frequency code element and these subcarriers.

On the other hand, a kind of device memory of comprising the processor of the pilot modulation error ratio that generates pilot frequency code element and being coupled to this processor in order to the storage information relevant with this pilot frequency code element.The average frequency domain channel estimating of each in a plurality of subcarriers of this processor generation RF signal superframe is also determined the noise variance of each pilot frequency code element in this superframe at least in part based on these average frequency domain channel estimating.The pilot modulation error of this pilot frequency code element is than at least in part based on the noise variance of this pilot frequency code element.

Aspect another, a kind of device comprises the device of each the average frequency domain channel estimating on the unit data of transmitter signal that is used for generating a plurality of subcarriers.This device also comprises each the device of pilot frequency code element noise that is used for determining to be associated with pilot frequency code element in these subcarriers based on each average frequency domain channel estimating of these a plurality of subcarriers, and the device that is used at least in part determining based on each pilot frequency code element noise of the subcarrier that is associated with this pilot frequency code element the average noise variance of this pilot frequency code element.In addition, this device comprises the device that is used at least in part generating based on each average frequency domain channel estimating of the average noise variance of this pilot frequency code element and these subcarriers the pilot modulation error ratio of indication transmitter performance.

On the other hand, a kind of computer-readable medium comprises the computer program that contains instruction, these instructions are used for: generate each average frequency domain channel estimating on the unit data of transmitter signal of a plurality of subcarriers, and each the pilot frequency code element noise of determining based on each the average frequency domain channel estimating in these a plurality of subcarriers to be associated with pilot frequency code element in these subcarriers.In addition, this computer program comprises the instruction that is used for following action: the pilot frequency code element noise of each that is associated with this pilot frequency code element based on these subcarriers is determined the average noise variance of this pilot frequency code element at least in part, and the pilot modulation error ratio that generates the indication transmitter performance at least in part based on the average noise variance of this pilot frequency code element and each the average frequency domain channel estimating in these a plurality of subcarriers.

Aspect another, a kind of processor is carried out the instruction that comprises following action: generate each the average frequency domain channel estimating on the unit data of transmitter signal in a plurality of subcarriers, and each the pilot frequency code element noise of determining based on each the average frequency domain channel estimating in these a plurality of subcarriers to be associated with pilot frequency code element in these a plurality of subcarriers.This processor also can be carried out the instruction that is used for following action: the pilot frequency code element noise of each that is associated with this pilot frequency code element based on these a plurality of subcarriers is determined the average noise variance of this pilot frequency code element at least in part, and the pilot modulation error ratio that generates the indication transmitter performance at least in part based on the average noise variance of this pilot frequency code element and each the average frequency domain channel estimating in these a plurality of subcarriers.

Address relevant purpose for before reaching, this or above embodiment are included in the feature of hereinafter fully describing and particularly pointing out in claims.Below explanation and appended illustration have elaborated some illustrative aspect of this or above embodiment.But these aspects only are some kinds that have indicated in the variety of way of the principle that can adopt each embodiment, and described embodiment is intended to contain all as in this respect and equivalent aspect.

The accompanying drawing summary

Fig. 1 is according to the diagram of the transmitter evaluation system of given or above aspect herein.

Fig. 2 is according to the diagram of the wireless communication system of given or above aspect herein.

Fig. 3 is according to the diagram of the wireless communication system of given or above aspect herein.

Fig. 4 is according to the diagram of the transmitter evaluation system of given or above aspect herein.

Fig. 5 is the example data structure of wireless system and the diagram of signal.

Fig. 6 be diagram record signal and transmit between the planisphere of difference.

Fig. 7 illustrates according to given in this article one or the method collection that is used to estimate transmitter of above aspect.

Fig. 8 illustrates the method collection of Modulation Error Rate that is used to generate pilot frequency code element according to given or above aspect herein.

Fig. 9 illustrates according to given herein one or the method collection that is used to estimate transmitter of above aspect.

Figure 10 illustrates according to given herein one or the method collection that is used to generate rough channel estimation of above aspect.

Figure 11 illustrates according to given herein one or the method collection that is used for determining modulated symbol of above aspect.

Figure 12 illustrates according to given herein one or the method collection that is used for determining modulated symbol of above aspect.

Figure 13 illustrates according to given one or above aspect are divided into a plurality of zonings with planisphere herein.

Figure 14 illustrates according to given herein one or the method collection that is used for determining modulated symbol during transmitter is estimated of above aspect.

Figure 15 illustrates according to the method collection that is used to estimate transmitter of the use phasing of given or above aspect herein.

Figure 16 illustrates according to given herein one or the method collection that is used for execution of phase correction of above aspect.

Figure 17 is the diagram according to the system of transmitter performance in the monitoring wireless communication environment of given or above aspect herein.

Figure 18 be can with the diagram of a kind of wireless communications environment of the various system and method couplings of describing herein.

Figure 19 is the diagram according to the system of transmitter performance in the evaluation wireless communications environment of given various aspects herein.

Specifically describe

With reference now to accompanying drawing, describes each embodiment, carry throughout in the accompanying drawings and use identical Reference numeral to quote from similar key element.In the following description, for ease of explaining, set forth numerous details to scheme to provide thorough to one or above embodiment.But it is evident that do not have these details also can put into practice this type of embodiment.In other example, known structure and equipment are shown in block diagram form in order to facilitate describes one or above embodiment.

As using in this application, term " assembly ", " system " and so on mean computer related entity, let alone combination, software, or the executory software of hardware, hardware and software.For example, but assembly can be but thread, program and/or the computer of the process that is not limited on processor, move, processor, object executive item, execution.As illustrating, the two can be assembly for the application that moves on communication equipment and this equipment.One or above assembly can reside in the thread of process and/or execution, and assembly can be localised on the computer and/or is distributed between two or the above computer.These assemblies also can store the various computer-readable mediums of various data structures from it and carry out.All assemblies can be communicated by letter by means of this locality and/or remote process, such as (for example according to signal with one or above packet, from the data of an assembly, wherein this assembly just by means of this signal and local system, distributed system and/or stride such as another component interaction in the network of internet etc. and the other system) do this and communicate by letter.

In addition, each embodiment relevant with subscriber equipment described in this article.Subscriber equipment also can be described as system, subscriber unit, subscriber station, mobile radio station, mobile device, distant station, access point, base station, remote terminal, accesses terminal, user terminal, terminal, user agent or subscriber's installation (UE).Subscriber equipment can be that cell phone, cordless telephone, Session Initiation Protocol phone, wireless local loop (WLL) are stood, PDA, have the portable equipment of wireless connections ability or be connected to other treatment facilities of radio modem.

In addition, various aspects or the feature of describing herein can use standard program and/or engineering to be implemented as method, device or manufacture.Being intended to contain as the term " manufacture " that uses in this article can be from the computer program of any computer readable device, carrier wave or medium access.For example, computer-readable medium can include but not limited to magnetic storage apparatus (for example hard disk, floppy disk, magnetic stripe ...), CD (for example, compact disk (CD), digital versatile disc (DVD) ...), smart card and flash memory device (for example, memory card, memory stick, key actuated device ...).

The FLO wireless system has been designed to both to have broadcasted real-time audio and vision signal is also broadcasted the non real-time service.FLO transmission be utilize that tall and big high power transmitter carries out to guarantee the extensive covering in the given geographic area.Usually in market, dispose a plurality of transmitters and arrive the signal portion of the total population in the given market to guarantee the FLO signal.

Usually, the FLO technology is utilized OFDM (OFDM).Generally frequency spectrum is divided into different channel such as OFDM etc. based on the technology of frequency division by frequency spectrum being split into uniform chunks of bandwidth.For example, the frequency spectrum or the frequency band that distribute for wireless cell phone signal post can be divided into 30 channels, wherein each channel portability voice dialogue, perhaps portability numerical data for digital service.Each channel only can be assigned to a subscriber equipment or terminal a time.On the OFDM actual effect total system bandwidth is divided into a plurality of orthogonal frequency channels.Ofdm system can use time-division and/or frequency division multiplexing to realize orthogonality between a plurality of transfer of data of a plurality of terminals.For example, different terminals can be assigned with different channels, and the transfer of data of each terminal can send distributing on the channel of this terminal.By using non-intersect or non-overlapping channel for different terminals, the interference between a plurality of terminals just can be avoided or be reduced, and can realize the performance of improving thus.

The overall performance that the base station transmitter performance is for wireless system---particularly utilizing the wireless system of FLO technology---is vital.Therefore, system and/or the method that is used to test and estimate transmitter should be accurately and have cost-efficient.It is tested before transmitter can or installed in factory to determine that transmitter conforms with the installation qualification.In addition, transmitter can be after installing tested or supervision to guarantee the transmitter performance continuous and effective.System and method described herein can be used to estimate the transmitter performance in the wireless environment, these wireless environments include, but are not limited to, the wireless environment of broadcasting FLO, DMB (DMB), digital video broadcasting (DVB), DVB-H, DVB-T, DVB-S or DVB-S2 signal.

Referring now to Fig. 1, illustrate the basis transmitter evaluation system 100 of given various aspects herein.System 100 can comprise the signal analyzer 104 of the signal that the transmitter 102 that can be used to sample is generated.By using signal analyzer 104 but not receiver receives this signal, receiver possible as extra noise and distortion source just can get rid of in system 100.System 100 also can comprise the signal that can processing signals analyzer 104 be captured and generate one or more processor modules of measuring 106 in order to the performance of estimating transmitter 102.Processor module 106 can comprise channel estimator assembly 108, and the latter can be used to generate the frequency domain channel estimation of this each subcarrier of receiving signal.This receives that signal is the signal of the former state receiving or record as evaluation system 100.Processor module 106 also can comprise generation such as based on one of the modulation error rate (MER) of pilot frequency code element etc. or above in order to the performance of estimating transmitter 102 measure measure maker assembly 110.Measuring the frequency domain channel that can be produced based on channel estimator assembly 108 at least in part of measuring that maker assembly 110 produced estimates.System 100 also can comprise the memory 112 that is connected to processor module 106, and the latter comprises the data relevant with evaluation of transmitter performance (for example, symbol data and metric data).In addition, system 100 can comprise that also the permission user comes the display module 114 of monitors transmitted machine performance by the visual feedback that processor module 106 generates.

Processor module 106 can be display module 116 various types of user interfaces is provided.Processor module 106 can provide graphic user interface (GUI), Command Line Interface etc.For example, can draw GUI in order to the zoning of checking transmitter information to the user is provided.This zoning can comprise known text and/or figure zoning, comprises dialog box, static control, drop-down menu, list box, popup menu, edit control, combo box, radio button, check box, button and graphical boxes.In addition, also can adopt such as the vertical and/or HScrollBar that is used to navigate and definite zoning and whether visible toolbar button etc. is helped the utility program that presents.

In an example, can adopt Command Line Interface.For example, this Command Line Interface can point out user's (for example, by text message on the display and tone) that information is provided by providing text message or this transmitter performance of warning user to drop on outside the predetermined margin.Should understand, Command Line Interface can use together in conjunction with GUI and/or application programming interfaces (API).In addition, Command Line Interface also can use together in conjunction with having hardware (for example, video card) that limited figure supports and/or display (for example, black and white and EGA) and/or low-bandwidth communication channel.

Also can generate alarm when in addition, evaluation system 100 is outside transmitter performance drops on predetermined tolerance interval and notify the user.This alarm can be audio frequency, vision or any other form of being intended to performance is notified the user.Evaluation system 100 can comprise the collection on the border of one group of predetermined indication tolerance interval.Perhaps, the user dynamically determines the border.In addition, evaluation system 100 also can generate alarm based on the change of transmitter performance.

Fig. 2 shows the only Radio Network System 200 of forward link network.System 200 comprises strides or the above transmitter 202 that wireless network 204 is communicated by letter with or above subscriber equipment or receiver 206.Receiver 206 can comprise such as the communication equipment of any kind in fact such as cell phone, computer, personal assistant, hand-hold type or laptop devices.The part of receiver 206 is used to decoded symbol subclass 208 and such as other data such as multi-medium datas.Symbol subset 208 generally is to adopt forward link (FLO) agreement only to carry out transmitting in OFDM (OFDM) network that multi-medium data transmits.

Fig. 3 is the diagram of wireless communication system 300.System 300 comprises the transmitter 302 that can receive the data that will transmit from communication satellite system 304.Can propagate by comprising the integrated receiver decoder 306 of satellite demodulator 308 and Simple Network Management Protocol (SNMP) control unit 310 from the signal of satellite system 304.Can be imported in the exciter 312 in the transmitter 302 from the signal data of integrated receiver decoder 306.In addition, transmitter 302 also can be connected to the Internet providers (IP) network 314 by modulator-demodulator 316.Modulator-demodulator 316 can be connected to the SNMP control unit 318 in the transmitter 302.Exciter 312 can comprise resolver and Single Frequency Network (SFN) buffer 320, Bowler core 322 and digital to analog converter (DAC) and I/O modulator 324.Signal data from satellite system 304 can resolved and storage in resolver and SFN buffer 320.Bowler core 322 can generate the plural number of this signal data of expression, and this signal data is passed to DAC and I/Q modulator 324 as homophase (I) and quadrature (Q) component.DAC and I/Q modulator 324 can utilize synthesizer 326 to handle this signal data and produce radio frequency (RF) signal of simulation.After these data were converted into simulation, the RF signal data that obtains can be transferred to power amplifier 328 and pass through harmonic filter 330.In addition, can make these data before by antenna 334 emissions, pass through channel model 332 earlier.

In order to estimate transmitter performance, the RF signal data that exciter 312 is produced can be monitored with the transmitter site error of emanating out earlier before emission.Possible transmitter site error or noise source comprise that rising sampling, digital-to-analogue conversion and RF changes.Signal data can be sampled in output place of exciter and in output place of channel model, so the RF signal can power amplification and filtering or before or after be sampled.If signal is to be sampled after amplifying, then also should proofread and correct signal at the power amplification non-linearity.

Referring now to Fig. 4, illustrate the transmitter evaluation system 400 that is connected to transmitter system exciter 312.Signal from global positioning system (GPS) receiver 402 can be used to synchro transmitter exciter 312 and signal analyzer 104.From the clock of the outside 10MHz of GPS receiver 402 can be fed to exciter 312 and signal analyzer 104 among both with as the common clock benchmark.For with the startup of signal analyzer 104 sampling synchronously to the beginning of the RF signal data superframe of exciter 312 outputs, GPS402 can send the signal of 1 pulse per second (1PPS) to exciter 312 and be used for synchronously and send the startup that signal analyzer 104 is used to trigger sampling to.The RF signal is made up of superframe, and wherein superframe can comprise that a group frame (for example, 4 frames) and frame are the logic units of data.Further particularly superframe is discussed with reference to Fig. 5.Signal analyzer 104 can be by generating the numeral sample of exciter simulation output waveform with the synchronous speed of the baseband chip rate that transmits.The data that sample can be fed in the processor module 106 subsequently.Processor module 106 can use general processor or be exclusively used in the processor of analyzing transmitter data and realize.Use general processor can reduce the cost of transmitter evaluation system 400.Signal analyzer 104 can be configured to the floating point mode operation to avoid quantizing noise.

Advance to Fig. 5, illustrate FLO physical layer superframe 500.In one embodiment, superframe can equal to have 1200 OFDM code elements of lasting duration in 1 second in 6MHz bandwidth situation.Generally speaking, the signal of FLO transmission is organized into the graphic superframe as 500 places.Each superframe can comprise four Frames, comprising TDM pilot frequency code element (through time division multiplexing) 502, overhead information symbols (OIS) 504 and comprise wide-area data 514 and the frame of local area data 516 506,508,510,512.Pilot frequency code element can comprise four predefined pilot frequency code elements: time division multiplexing 1 (TDM1), wide area sign channel (WIC), local sign channel (LIC) and time division multiplexing 2 (TDM2).These pilot frequency code elements can be used to synchronously, regularly and purpose such as sign.Therefore, the structure of pilot frequency code element is different with the OFDM data symbols that is comprised with four Frames 506,508,510 and 512.Pilot frequency code element can allow catching fast OIS.OIS describes the position of the data of each media services in this superframe.

Usually, each superframe comprises 200 OFDM code elements of bandwidth (1200 code elements being arranged for 6MHz) that every MHz distributes, and each code element can comprise 7 bursts of active sub-carriers and interweaves.For example, each code element can comprise 4096 subcarriers, and wherein 4000 subcarriers can use for data.Per share active sub-carriers interweaves and evenly distributes on frequency, so makes it realize the full rate diversity in the available bandwidth.These interweave with being assigned in reality and use different logic channel on the lasting duration interweave and the number meaning.This provides flexibility for the time diversity that any given data source realized.The channel of lower data rate can be assigned less interweaving to improve time diversity, interweaves to minimize the wireless operating time and to reduce power consumption and the channel usage of higher data.

The capture time of low data rate channel and High Data Rate channel generally is identical.Therefore, can under the situation that does not bring disaster to capture time, keep frequency and time diversity.Modal is that the FLO logic channel is used to carry real-time (live stream is sent) content under the variable bit rate so that obtain with variable rate codec (compressor reducer and decompressor one) statistical multiplexing gain in the cards.Each logic channel can have different encoding rates and modulate to support the various reliabilities and the quality of service requirement of different application.The FLO multiplexing scheme make the equipment receiver can demodulation it the content of interested single logic channel with minimizing power dissipation.The a plurality of logic channels of mobile device demodulation concomitantly are so that video and the audio frequency that is associated can send on different channels.

Referring now to Fig. 6, show diagram receive or record signal and transmit between the planisphere of difference.The real component and the imaginary component of the axle expression plural number of this planisphere---be called as homophase or I axle and quadrature or Q axle.Receive or record signal constellation point and the vector representation error between the constellation point of transmitting, this error may comprise amplitude ripple, transmitter IFFT quantization error etc. in digital-to-analogue conversion inaccuracy, non-linearity of power amplifier, the band.

The transmitter evaluation system can generate in order to one or more of the performance of estimating transmitter and measure.Measuring that processor generates includes but not limited to Modulation Error Rate (MER), pilot modulation error ratio, group delay or channel frequency response.Particularly, MER weighs the cumulative effect of spots in the transmitter.The MER of subcarrier is equivalent to the signal to noise ratio (snr) of subcarrier.MER can use following formula to generate:

$\mathrm{MER}\left(\mathrm{dB}\right)=10\log \frac{\frac{1}{N}\underset{1}{\overset{N}{\mathrm{\&Sigma;}}}({\mathrm{<figure-callout\; id="2"\; label="I"\; filenames="A200780012903E00321.png"\; state="\{\{state\}\}">I</figure-callout>}}^2+Q^2)}{\frac{1}{N}\underset{1}{\overset{N}{\mathrm{\&Sigma;}}}({\mathrm{\&Delta;<figure-callout\; id="2"\; label="I"\; filenames="A200780012903E00321.png"\; state="\{\{state\}\}">I</figure-callout>}}^2+\mathrm{\&Delta;}{Q}^2)}$

Here, I is the in-phase value that records constellation point, and Q is the quadrature value that records constellation point, and N is the number of subcarrier.Δ I transmits and records difference between the in-phase value of signal, and Δ Q transmits and records difference between the quadrature value of signal.

Each that can be in these four pilot frequency code elements determines that respectively independent pilot tone MER measures.The pilot tone MER of each in these pilot frequency code elements can be each pilot frequency code element single quality factor is provided.The calculating of pilot tone MER or generation are specifically discussed with reference to Fig. 8.

With reference to Fig. 7-12 and 14-16, illustrate with estimate wireless communication system in the relevant method collection of transmitter performance.Although explain that for making simplification illustrates and be described as a series of actions with these method collection, but be to be understood that and understand, the order that these method collection are not moved is limit, because according to one or above embodiment, some actions can be by being different from that the order that illustrates and describe takes place herein and/or taking place concomitantly with other actions.For example, those skilled in the art it will be appreciated that and understand that the method collection can be expressed as a series of state or incidents of being mutually related with being replaced, just as in state diagram.In addition, can not be that the action that utilizes all to illustrate realizes method collection according to one or above embodiment.

Referring now to Fig. 7, illustrate and be used to handle RF signal data that is received from transmitter and the method collection 700 of estimating transmitter performance.702, receive or this signal of sampling from transmitter.It is as follows to receive that signal can be written as:

Y _k＝H _k·P _k+N _k

Here, H _kIt is the channel of subcarrier k.Known modulation symbol P _kCan on subcarrier k, be transmitted.Zero-mean and variance are σ ²Plural additive white Gaussian noise (AWGN) can be by N _kRepresent.

It is that layering QPSK, 16QAM (quadrature amplitude modulation) and the energy ratio of 6.25 (ER6.25) is the layering QPSK of 4.0 (ER4) that the possible modulation type of the subcarrier of OFDM data code element can include, but are not limited to Quadrature Phase Shift Keying (QPSK), energy ratio.The subcarrier of pilot frequency code element is generally the QPSK modulation type.When analyzing based on the viewpoint of constellation, energy is equal to the modulation type of 16QAM than the layering QPSK modulation type that is 4.0.As used in this, the constellation viewpoint is meant and utilizes planisphere to represent digital modulation scheme in complex plane.Modulated symbol can be represented as the constellation point on the planisphere.

Can estimate in the initial frequency domain channel of 704 definite subcarriers.The initial channel estimation of each subcarrier can be by the signal Y with subcarrier k _kKnown symbols P divided by subcarrier k _kObtain.Can launch selected code element, so make these code elements known for the purpose of performance evaluation.For example, the test period before installation can be launched specific symbol pattern and so make the code element of each subcarrier be measurable and be known thus.When the modulated symbol of emission is unknown, determine modulated symbol specifically discussion hereinafter.The initial frequency domain channel of each subcarrier k of each OFDM code element l is estimated and can be expressed as followsin in the superframe:

$Z_{k,l}=Y_{k,l}/P_{k,l}=H_{k,l}+\frac{N_{k,l}\&CenterDot;P_{k,l}^{*}}{{\left|P_{k,l}\right|}^2}$

Here, Z _{K, l}It is initial channel estimation to subcarrier k and OFDM code element l.

Can be in the average channel estimation of 706 definite each subcarrier.The channel estimating Z of subcarrier _{K, l}Can refine by on whole superframe, being averaged, so make:

${\hat{H}}_k=H_k+\frac{1}{L}\underset{1=0}{\overset{L-1}{\mathrm{\&Sigma;}}}\frac{N_{k,1}\&CenterDot;P_{k,1}^{*}}{{\left|P_{k,1}\right|}^2}$

Here, k is an OFDM symbol index and L is the number (for example, 1188 code elements) of OFDM code element in the superframe.Because the variance of average channel estimation is less than the variance of initial channel estimation, so the variance of average channel estimation can be used to the approximate channel gain of measuring this subcarrier during the generation.

708, generate one or more that be used to estimate transmitter performance and measure.For example, can generate the MER of the data symbols of subcarrier k.The OFDM data symbols of supposing emission is known, and then noise variance can be estimated by following formula:

$W_{k,m}=Y_{k,m}-{\hat{H}}_k{\&CenterDot;X}_{k,m}=N_{k,m}-\frac{1}{L}\underset{l=0}{\overset{L-1}{\mathrm{\&Sigma;}}}\frac{N_{k,l}\&CenterDot;X_{k,l}^{*}}{{\left|X_{k,l}\right|}^2}\&CenterDot;X_{k,m}$

Here, X _{K, m}The transmit symbol of vice carrier wave k.Can prove, if stochastic variable B _kBe that the noise variance that estimates is so feasible:

$B_k=\frac{1}{L-1}\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}{W}_{k,\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="A200780012903E00321.png"\; state="\{\{state\}\}">l</figure-callout>}}^2$

And:

$E\left(B_k\right)=\frac{L}{L-1}E\left(W_k^2\right)={\mathrm{\&sigma;}}^2$

This noise W then _kHomophase and quadrature component be approximately:

$N(0,(1-\frac{1}{L})\frac{{\mathrm{\&sigma;}}^2}{2})$

The MER of subcarrier can determine based on the average channel estimation of this subcarrier, the code element that transmits on this subcarrier and to the signal that this subcarrier receives.MER can calculate based on following exemplary equation:

${\mathrm{MER}}_k=\frac{E{|H_k\&CenterDot;P_k|}^2}{E{|Y_k-H_k\&CenterDot;P_k|}^2}=\frac{E{\left|H_k\right|}^2\&CenterDot;E{\left|P_k\right|}^2}{E{\left|N_k\right|}^2}\&ap;\frac{E{\left|{\hat{H}}_k\right|}^2\&CenterDot;E{\left|P_k\right|}^2}{E\left(B_k\right)}$

Here,

Be the average channel estimation of subcarrier k, P _kBe the code element that on this subcarrier, transmits, Y _kBe to receive signal, and N _kBe AWGN.In addition, MER can calculate by being averaged on all subcarriers.

Except the MER that uses the OFDM data symbols to generate, also can generate one or above pilot modulation error than or be pilot tone MER.Pilot tone MER is specific to one of special pilot code element (for example, TDM1, WIC, LIC and TDM2).Because the difference between pilot frequency code element and the data symbols, pilot tone MER differs from OFDM data symbols MER.In addition, pilot frequency code element is identical on all superframes.Therefore, no matter transmit what data symbols, pilot frequency code element all is known.

Referring now to Fig. 8, illustrate the method collection 800 that is used to generate pilot tone MER.Can be in these pilot frequency code elements (for example, TDM1, WIC, LIC and TDM2) each or any which generate pilot tone MER.802, can calculate the noise or the error of each active sub-carriers in this pilot frequency code element.The subcarrier that these pilot frequency code elements used is called as active sub-carriers here, and untapped subcarrier can be called as non-active sub-carriers.For in these four pilot frequency code elements each, may use predetermined sets of subcarriers to transmit this pilot frequency code element.With whole or most OFDM data symbols formation contrasts that may be used to transmit data of these subcarriers therein, pilot frequency code element may utilize the central significantly much smaller part of these subcarriers.For example, in the middle of 4000 available subcarriers, the TDM1 pilot tone may therefrom be utilized 124 subcarriers, and the TDM2 pilot frequency code element may therefrom utilize 2000 subcarriers and WIC and LIC pilot frequency code element may therefrom utilize 500 subcarriers separately.For active sub-carriers, the noise of each subcarrier of one of these four pilot frequency code elements can use following exemplary equation to generate:

$W_{k,l}=Y_{k,l}-{\hat{H}}_k\&CenterDot;X_{k,l}$

Here, W _{K, j}Be noise or the error of subcarrier k, and l represents one of these four pilot frequency code elements (for example, TDM1, WIC, LIC and TDM2), so have l ∈ 0,1,2,3}.As discussed above, Y _{K, l}It is the signal that subcarrier k and pilot frequency code element l are received. Be the average channel estimation of subcarrier k on superframe, and X _{K, l}The modulated symbol that expression is transmitted the subcarrier k of pilot frequency code element l.For pilot frequency code element, code element is known.Therefore, can calculate noise or error.

804, can determine the noise of all non-active sub-carriers of this pilot frequency code element.For non-active sub-carriers, can use following exemplary equation to determine noise:

W _k，l＝Y _k，l

Here, because these subcarriers are not used to pilot frequency code element, be noise so receive signal.

806, after calculating noise or error in these subcarriers of this pilot frequency code element each, can use following exemplary equation to stride the average noise variance of all these subcarriers for this pilot frequency code element generation

$B_l=\frac{1}{4000+\frac{N_l}{L}}\underset{m}{\overset{4000}{\mathrm{\&Sigma;}}}{\left|W_{m,l}\right|}^2$

Here, N _lIt is the number of the active sub-carriers of OFDM code element l.For example, for TDM1, N _lMay be 124, for TDM2, N _lMay be 2000, and for WIC and LIC, N _lMay be 500.The noise variance of all subcarriers of this pilot frequency code element is got summation.The summation of noise variance is added calibration factor N by the number (for example, 4,000) divided by subcarrier _l/ L, wherein L is a constant.Scaling factor can be used to guarantee that pilot tone MER is suitable with the MER that uses the OFDM data symbols to generate on scale.Compare the active remarkable much less of subcarrier for pilot frequency code element with the OFDM data symbols.The signal power of the signal power of OFDM pilot frequency code element and OFDM data symbols is same or similar.In order to produce equal signal power with the active sub-carriers of remarkable much less, the division ratio data symbols of the active sub-carriers of pilot frequency code element much higher.Can make the number of the scaling factor of the noise variance that is used for determining pilot frequency code element, to guarantee the suitable of noise variance and OFDM data symbols based on the active sub-carriers of pilot frequency code element.

After calculating noise variance, at the 808 pilot tone MER that can calculate or above pilot frequency code element.Following exemplary equation can be used to calculate the MER of any which l in these pilot frequency code elements:

${\mathrm{MER}}_l=\frac{1}{4000}\frac{\underset{k}{\overset{4000}{\mathrm{\&Sigma;}}}{\left|{\hat{H}}_k\right|}^2{\left|X_{k,l}\right|}^2}{B_l}$

Here

Be still the average channel estimation of subcarrier k, X _{K, l}Be the known modulation symbol of the subcarrier k of pilot frequency code element l, and B _lIt is the noise variance of pilot frequency code element l.Each that can be in these four pilot frequency code elements (for example, TDM1, WIC, LIC and TDM2) generates pilot tone MER.

Referring now to Fig. 9, illustrate the method collection 900 that is used for estimating transmitter in the occasion of the code element the unknown of launching.When modulated symbol (for example, QPSK or 16QAM code element) when transmitting real time data stream is unknown.Yet pilot frequency code element is known.902, receive signal.In the 904 rough initial channel estimation that can generate these subcarriers.Rough initial channel estimation can use known pilot symbols and linear interpolation and extrapolation to carry out, and describes with reference to Figure 10 as following.906, determine the modulated symbol of these subcarriers.These modulated symbols can such as following about Figure 11 to 14 description ground use planisphere to determine.These modulated symbols can be based on receiving that the distance between signal constellation point and the hithermost modulated symbol constellation point selects.Code element is chosen in followingly to be described more specifically.908, can determine that the initial frequency domain channel of each subcarrier is estimated.The initial channel estimation of each subcarrier can be by receiving that signal obtains divided by modulated symbol.

910, on superframe, channel estimating is averaged to increase accuracy.Average channel estimation can be used rough channel estimation, determine based on channel estimating or this two groups of channel estimating of modulated symbol.Can generate at least in part based on these channel estimating, be used to estimate transmitter one or more 912 and to measure.For example, the MER of each subcarrier can determine based on these channel estimating and modulated symbol, as above specific descriptions.In addition, also can generate the pilot tone MER of each pilot frequency code element.

Referring now to Figure 10, illustrate the method collection 1000 that is used to generate rough channel estimation.As above concrete discuss, receive that signal can be write as the code element of channel estimating, this subcarrier and the function of noise item AWGN.In each OFDM code element, there is the subcarrier of predetermined number to carry the known pilot frequency code element of receiver (for example, 500 subcarriers carry pilot tone QPSK code element).Therefore, for this subsets of subcarriers, modulated symbol is known.Therefore, in 1002 channel estimating that can calculate these pilot subcarriers.1004, can use linear interpolation to obtain the channel estimating of the subcarrier between two pilot subcarriers.The channel estimating of the subcarrier that---is not between pilot subcarrier therefore---1006, at the superframe two ends can use linear extrapolation to obtain.

In addition, there is the pilot frequency code element of (2,6) pattern staggered, estimates so 500 pilot tone boths of 500 pilot tones of current OFDM code element and last OFDM code element can be used to obtain frequency domain channel for each OFDM code element of superframe.In situation like this, the channel estimating of pilot subcarrier is to use pilot frequency code element to generate, and the channel estimating of all the other subcarriers obtains by linear interpolation or extrapolation.

Referring now to Figure 11, illustrate the method collection 1100 that is used for determining modulated symbol.1102, calculate the distance between the constellation point of the constellation point receive signal and possible modulated symbol.For example, can calculate and receive signal constellation point and the distance between the QPSK constellation point of close this signal constellation point and this signal constellation point and the distance between the 16QAM constellation point of close this signal constellation point.1104, the modulated symbol constellation point of close this signal constellation point is selected as modulated symbol.In order to increase the accuracy that modulated symbol is selected, this modulated symbol can be compared with the modulation type of the subsets of subcarriers with consistent modulation type.The mistake that modulated symbol is selected can check that the modulation type of subcarrier avoids by the modulation type that contrasts this subsets of subcarriers.At 1106 modulation types that can determine this subsets of subcarriers.1108, determine whether this modulated symbol is consistent with this modulation type.If then this process stops.If not, then reappraise this modulated symbol and selection and the corresponding to modulated symbol of this modulation type 1110.

Usually, modulation type is consistent during partly interweaving.Partly interweave and be used as the example of subsets of subcarriers at this with consistent modulation type.Yet in the system and method for being discussed, the subsets of subcarriers with consistent modulation type is not limited to partly interweave in this article.Generally speaking, because the constraint in the FLO agreement, modulation type does not change in interweaving.Interweaving as used in this is sets of subcarriers (for example, 500 subcarriers).Therefore, partly interweaving is half (for example, 250 subcarriers) that interweave.Yet for 2/3 rate hierarchical modulation, when being operated in only basic unit's pattern following time, modulation type may be switched to QPSK in interweaving.Even under these situations, the modulation type in whenever partly interweaving still keeps constant.Therefore, the modulation type that whenever partly interweaves can use majority voting to determine.In order to determine partly to interweave or any other has the modulation type of the subsets of subcarriers of consistent modulation type, can to determine modulated symbol and determine modulation type thus each subcarrier in this subclass.Can be used to determine the modulation type of this subclass based on majority voting with the corresponding modulation type of each subcarrier.For example, for comprising partly interweaving of 250 subcarriers, wherein the modulation type of 198 subcarriers may be consistent with the QPSK modulation type, and the modulated symbol of all the other 52 subcarriers may be consistent with the 16QAM modulation type.Because the great majority in the subcarrier are detected as QPSK, so QPSK will be chosen as the modulation type that this partly interweaves.Can reappraise and they are assigned to the QPSK modulated symbol again these 52 subcarriers that are associated with the 16QAM modulation type based on their positions in planisphere.The sub-carrier modulation code element compared with the modulation type that partly interweaves and reappraise the sub-carrier modulation code element as required and increased the accuracy that modulated symbol is selected.

Referring now to Figure 12-13, illustrate the method collection 1200 that is used for determining modulated symbol among Figure 12.1202, comprise that the planisphere of the constellation point of representing each modulated symbol is divided into a series of zonings.Each zoning is associated with a modulated symbol constellation point.Zoning is defined by making each point in each zoning have such attribute---promptly so some distance to the constellation point of this zoning is less than or equal to point like this and takes office the what distance of the constellation point of its zoning.Illustrate one group of zoning of the first quartile that covers planisphere among Figure 13.1204, determine to receive that signal constellation point is positioned at zoning wherein.Be chosen as modulated symbol with receiving the corresponding modulated symbol of zoning that signal constellation point is positioned at wherein.The modulation type that can contrast the subsets of subcarriers (for example, partly interweaving) with consistent modulation type is checked this modulated symbol.At 1206 modulation types that can determine this subsets of subcarriers.1208, determine whether this modulated symbol is consistent with this modulation type.If then this process stops.If not, then reappraise this modulated symbol and selection and the corresponding to modulated symbol of this modulation type 1210.If the modulation type of this modulated symbol and this subclass is inconsistent, then select and the corresponding to modulated symbol of this modulation type.

Referring now to Figure 14, illustrate the modulation type of the subsets of subcarriers (for example, partly interweaving) that is used to determine to have consistent modulation type and the method collection 1400 of modulated symbol.1402, determine the modulated symbol constellation point of close signal constellation point at each modulation type.Determine the hithermost modulated symbol constellation point of corresponding every kind of modulation type for each subcarrier.For example, if three kinds of possible modulation types (for example, 16QAM, ER4 and ER6.25) are arranged, then determine three hithermost modulated symbol constellation point for each subcarrier in this subsets of subcarriers---one every type.

The hithermost modulated symbol constellation point of certain modulation type can be received the distance between signal constellation point and the possible modulated symbol constellation point and selects to determine corresponding to the modulated symbol constellation point of minimum range by calculating.Perhaps, hithermost modulated symbol constellation point can use zoning to determine.The hithermost modulated symbol constellation point of certain modulation type can be determined by planisphere being divided into corresponding several zonings of the modulated symbol of this modulation type.Zoning is defined by so making each point in each zoning have such attribute---promptly so some distance to the constellation point of this zoning is less than or equal to point like this and takes office the what distance of the constellation point of its zoning.Be positioned at the hithermost modulated symbol constellation point that wherein the corresponding modulated symbol of zoning is chosen as this certain modulation type with receiving signal constellation point.

1404,, then determine distance between this signal constellation point and each the hithermost modulated symbol point for each subcarrier in this subsets of subcarriers if do not calculate this distance in the above.No matter be before or 1404 to calculate this distance, all the distance value with every kind of modulation type of correspondence is associated with each subcarrier.For example, if three kinds of possible modulation types are arranged, then each subcarrier in this subclass will have three distance values that are associated with it.In these distance values each is corresponding with one of these three kinds possibility modulation types.This distance value can be calculated as the hithermost modulated symbol constellation point of certain modulation type and the minimum range between this signal constellation point square.

1406, every kind of modulation type is generated measuring on this subclass.Measuring of corresponding certain modulation type can generate by each subcarrier in this subclass is got summation to square distance value that should modulation type.Perhaps, measuring of corresponding certain modulation type can generate by each subcarrier in this subclass is averaged distance value that should modulation type.1408, can measure the selection modulation type based on what generated.For example, be to generate if this is measured by the square distance value of corresponding certain modulation type of each subcarrier in this subclass is got summation, then selected modulation type should be corresponding to having measuring of minimum value.In case selected the modulation type of this subclass, then can will put the modulated symbol of corresponding modulated symbol with the hithermost modulated symbol of selected modulation type as this subcarrier 1410.

Transmitter evaluation system described herein and method also should comprise and be intended to reduce or eliminate the error that caused by time and frequency-offset or the phasing of distortion.If execution of phase correction not, then channel estimating on average may be inaccurate, and estimates thus that measure may be incorrect.Usually, phasing can before channel estimating is averaged, carry out with at since the caused phase ramp of frequency shift (FS) proofread and correct.

Referring now to Figure 15, illustrate the method collection 1500 that is used for estimating transmitter that uses phasing.1502, receive signal from transmitter.In 1504 channel estimating that can determine all subcarriers.These channel estimating can be determined as known symbols that Fig. 7 diagrammatically uses or as unknown code element that Fig. 9 diagrammatically uses.1506, but execution of phase correction.After phasing, can determine average channel estimation 1508.1510, can generate one or more that be used to estimate transmitter performance and measure.For example, can determine the MER of subcarrier and/or can be one or above generation pilot tone MER in these pilot frequency code elements based on channel estimating.

Referring now to Figure 16, illustrate the method collection 1600 that is used for correcting frequency shift.The signal of receiving that comprises frequency shift (FS) can be write as follows:

$r\left(t\right)=\underset{n=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{R}_n{e}^{j({\mathrm{\&omega;}}_0+n{\mathrm{\&omega;}}_s+\mathrm{\&Delta;\&omega;})t}$

Here, R _nBe the complex amplitude of n subcarrier, and N is the sum of subcarrier.The frequency of initial sub carrier is by ω ₀Expression, ω _sVice intercarrier distance, and Δ ω is frequency shift (FS).Constant frequency shift (FS) will cause that linear phase change is arranged in time.The frequency shift (FS) of change will cause that parabolical phase change is arranged as time passes linearly in time.No matter constant the still frequency shift (FS) of linear change all cause the measurable phase change that can be corrected earlier as illustrated in fig. 15 before being averaged.

Linear phase changes can use single order phasing algorithm to proofread and correct by the slope that calculates phase change.For example, phase change can be calculated as follows:

Here,

Be two phase change of adjoining channel estimating between the OFDM code element, Be the phase place of initial channel estimation, L is the number of OFDM code element and T _OFDMIt is the cycle.

Parabolical phase change can use the second order phasing to proofread and correct by parameter a, b and the c that determines this parabolic function with the LS algorithm.The phase place that estimates can be write as follows:

Here, t is the time.The phase place that estimates can be used to proofread and correct earlier the channel that estimates before being averaged.

Yet frequency shift (FS) might not be constant or linear change.Therefore, phase change might not be linearity or parabola and predictable.A kind of possible scheme that skew is proofreaied and correct to variable frequency comprises the duration section of being divided into and estimates phase change at each section subsequently.Therefore, about the described MER of Fig. 7 _kThe noise variance B that estimates in the equation _kShould be modified as follows:

$B_k=\frac{2}{2L-N-1}\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}{W}_{k,\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="A200780012903E00321.png"\; state="\{\{state\}\}">l</figure-callout>}}^2$

Here, N is a hop count.

Can be broken down into two orthogonal dimension from the noise item of each channel of receiving each OFDM code element that signal is derived: amplitude peacekeeping phase place dimension.Noise item in the amplitude dimension can be regarded as additive white Gaussian noise.Noise item on the phase directional can be regarded as additive white Gaussian noise (AWGN) and the summation that is derived from the distortion of frequency shift (FS).The distortion that frequency shift (FS) caused should be eliminated.Yet the AWGN component in the phase place dimension should be held.

Shown in graphic method collection 1600 among Figure 16, determine the hop count that the time will be divided into 1602.1604, estimate because the caused phase change of frequency shift (FS) at section.Proofread and correct this section at 1606 uses or single order or second order correction algorithm.1608, definite about whether having more multistage to proofread and correct to make.If have, then this process turns back to 1604 to determine the phasing at next section.If do not have, then this process stops.

In a kind of egregious cases, if the variance of noise equals the variance of noise in the phase place dimension, the number of the OFDM code element that then maximum hop count equals handling in the amplitude dimension.Therefore, noise in the phase place dimension and the distortion that causes owing to frequency shift (FS) all will be eliminated.Therefore, comprise that MER that the actual value of the MER of the noise in the phase place dimension will equal to be generated deducts a constant (for example, 3.01dB) resulting value.

Can understand, one or above embodiment according to described herein can draw an inference about transformat, frequency etc.As used in this article, term " infer (verb) " or " inferring (noun) " general reference are from as via incident and/or data capture one group of process of observing reasoning or inference system, environment and/or state of user to former state.For example, can adopt deduction to identify concrete context or action, maybe can generate the probability distribution on all states.Deduction can be probabilistic---that is, based on the probability distribution of consideration calculating on interested state of data and incident.Infer the technology can also refer to be used for constitute higher level incident from one group of incident and/or data.So infer and cause the incident or the action that make new advances from one group of observed incident and/or the event data structure stored, no matter whether these incidents are closely related on property meaning around, and also no matter these incidents and data are from one or several incidents and data source.

According to an example, more than one or more given methods may comprise that the hop count that will utilize about phasing draws an inference.Also can draw an inference about the type of measuring and the number that will generate to estimate transmitter.In addition, can be about drawing an inference to user's data presented and form.

Figure 17 provides the diagram to the system 1700 of the supervision of transmitter performance in the communication environment.System 1700 comprises base station 1702, it has via or above reception antenna 1706 and receives receiver 1710 from the signal of or above subscriber equipment 1704, and by one or above transmitting antenna 1708 to one or 1704 emissions of above subscriber equipment.In one or above embodiment, reception antenna 1706 and transmitting antenna 1708 can use single group antenna to realize.Receiver 1710 can be from reception antenna 1706 reception information, and onset ground and demodulate reception to the demodulator 1712 of information be associated.Can understand as those skilled in the art, receiver 1710 can be that for example rake receiver is (for example, use a plurality of baseband correlators individually to handle the technology of multi-path signal-component ...), the receiver that branches away based on the receiver of MMSE or other certain each subscriber equipment of being suitable for being assigned to it.According to various aspects, can adopt a plurality of receivers (for example, one of every reception antenna), and so receiver can communicate with one another so that the user data estimation of improvement to be provided.Code element through demodulation is analyzed by processor 1714.Processor 1714 can be that be exclusively used in the information that analysis receiver assembly 1714 receives and/or generate will be by the information processing device of transmitter 1714 emissions.Processor 1714 can be or the processor of above assembly of control base station 1702, and/or the information that receives of analysis receiver 1710, generates and will and control one or the processor of above assembly of base station 1702 by the information of transmitter 1720 emissions.The receiver output of each antenna can be by receiver 1710 and/or processor 1714 Combined Treatment.Modulator 1718 reusables will be by transmitter 1720 by the signal of transmitting antenna 1708 to subscriber equipment 1704 emissions.Processor 1714 can be coupled to FLO channel element 1722, and the latter can help to handle the FLO information that is associated with one or above respective user equipment 1704.

Modulator 1718 reusables will be by transmitter 1720 by the signal of transmitting antenna 1708 to subscriber equipment 1704 emissions.FLO channel element 1722 can transmit this information to subscriber equipment 1704 indication that identifies and confirm new preferred channels is provided to the additional information relevant with the more new data stream of given transport stream of signal so that link up with subscriber equipment 1704.

Base station 1702 also can comprise transmitter monitor 1724.Transmitter monitor 1724 can be exported the performance of sampling and estimating transmitter 1720 to transmitter output and/or transmitter antenna.Transmitter monitor 1724 can be coupled to processor 1714.Perhaps, transmitter monitor 1724 can comprise the separate processor that is used to handle transmitter output.In addition, transmitter monitor 1724 can be independent of base station 1702.

Base station 1702 can comprise memory 1716 in addition, be coupled to its onset processor 1714 and can store the information relevant with constellation zoning, modulated symbol and/or any other with carry out the exercises of being set forth and the appropriate information of function herein.Can understand, the storage of Miao Shuing (for example, memory) assembly or can be volatile memory or can be nonvolatile memory maybe can comprise volatibility and nonvolatile memory herein.Non-limiting by illustration, nonvolatile memory can comprise read-only memory (ROM), programming ROM (PROM), electrically programmable ROM (EPROM), electric erasable type ROM (EEPROM) or flash memory.Volatile memory can comprise random-access memory (ram), and it plays the part of the role of outside speed buffering formula memory.Non-limiting by illustration, RAM has many forms to use, such as synchronous random access memory (SRAM), dynamic ram (DRAM), synchronous dram (SDRAM), double data rate SDRAM (DDR SDRAM), enhancement mode SDRAM (ESDRAM), synchronization link DRAM (SLDRAM) and direct rambus RAM (DRRAM).The memory 1716 of system and method for the present invention is intended to contain and is not limited to the memory of these and any other adequate types.

Figure 18 shows example wireless communications 1800.For for purpose of brevity, wireless communication system 1800 has been described a base station and a subscriber equipment.But should understand, this system can comprise more than one base station and/or more than one subscriber equipment, and base station that wherein adds and/or subscriber equipment can be similar substantially or different with subscriber equipment with the exemplary base that describes below.In addition, base station and/or subscriber equipment should be understanded and system described herein (Fig. 1,3-4 and 18) and/or method (Fig. 7-12 and 14-16) can be adopted.

Now referring to Figure 18, on the down link, at access point 1805 places, emission (TX) data processor 1810 receives, formats, encodes, interweaves, also modulates (or symbol mapped) traffic data and modulated symbol (" data symbols ") is provided.Symbol modulator 1815 receives and handles these data symbols and pilot frequency code element and code element stream is provided.Symbol modulator 1815 is multiplexing and provide it to transmitter unit (TMTR) 1820 with data and pilot frequency code element.Each transmit symbol can be data symbols, pilot frequency code element or signal value of zero.Pilot frequency code element can be sent in each code-element period continuously.Pilot frequency code element can be by frequency division multiplexing (FDM), OFDM (OFDM), Time Division Multiplexing, frequency division multiplexing (FDM) or code division multiplexing (CDM).

TMTR1820 receiving code flow filament also converts thereof into one or be adapted at the down link signal that transmits on this wireless channel with generation with analog signals step reason (for example, amplification, filtering and up-conversion) these analog signals of going forward side by side.This down link signal is launched to all subscriber equipmenies by antenna 1825 immediately.At subscriber equipment 1830 places, antenna 1835 receiving downlink signals also offer receiver unit (RCVR) 1840 with the signal that receives.The signal that receiver unit 1840 conditionings (for example, filtering, amplification and down-conversion) receive also will be sampled with acquisition through the signal digitalized of conditioning.Symbol demodulator 1845 demodulate reception to pilot frequency code element and provide it to processor 1850 and make channel estimating.Symbol demodulator 1845 further receives at the frequency response of down link from processor 1850 to be estimated, the data symbols that receives is carried out data demodulates estimate (it is the estimation to the data symbols that transmits) to obtain data symbols, and these data symbols are estimated to offer RX data processor 1855, the traffic data that latter's demodulation (that is symbol de-maps), deinterleaving and these data symbols estimations of decoding are transmitted to recover.The processing complementation that the processing of being undertaken by symbol demodulator 1845 and RX data processor 1855 is undertaken by symbol modulator 1815 and TX data processor 1810 with access point 1805 places respectively.

On up link, TX data processor 1860 processes traffic data also provide data symbols.Symbol modulator 1865 receives these data symbols and itself and pilot frequency code element is multiplexing, carries out modulation, and code element stream is provided.Transmitter unit 1870 receives and handles this code element stream then to generate uplink signal, and this signal is launched to access point 1805 by antenna 1835.

At access point 1805 places, received by antenna 1825 from the uplink signal of subscriber equipment 1830, and handle to obtain sample by receiver unit 1875.Symbol demodulator 1880 is handled these samples immediately and is provided and receives pilot frequency code element and estimate at the data symbols of this up link.RX data processor 1885 is handled these data symbols and is estimated to recover the traffic data that subscriber equipment 1830 is transmitted.Each active user equipment that 1890 pairs of processors transmit on up link is carried out channel estimating.A plurality of subscriber equipmenies can transmit pilot tone on the up link concomitantly on the pilot subcarrier collection that it is assigned separately, wherein all pilot subcarrier collection can be interleaved.

Processor 1890 and 1850 instructs the operation at (for example, control, coordination, management etc.) access point 1805 and subscriber equipment 1830 places respectively.Corresponding each processor 1890 and 1850 is associated with program code stored and memory of data unit (not shown ).Processor 1890 and 1850 can utilize any method collection described herein. Respective processor 1890 and 1850 also can be carried out the calculating that derivation is estimated at the frequency and the impulse response of up link and down link respectively.

Realize that for software the technology of Miao Shuing can realize with the module (for example, process, function or the like) of carrying out the function of describing herein herein.Software code can be stored in the memory cell and by processor and carry out.Processor can be realized or be placed on to memory cell in processor, it can be coupled to processor communicatedly via various means known in the art in a kind of situation in back.

Referring now to Figure 19, illustrate according to given herein one or the system that helps to estimate the transmitter performance in the wireless communications environment 1900 of above aspect.System 1900 can comprise the device 1902 of each the average frequency domain channel estimating on the transmitter signal superframe that is used for generating a plurality of subcarriers.System 1900 also can comprise and being used for based on the pilot frequency code element noise of the definite subcarrier that is associated with pilot frequency code element of these average frequency domain channel estimating or the device 1904 of error.In addition, system 1900 also can comprise the device 1906 that is used at least in part determining based on the pilot frequency code element noise of each subcarrier of the sets of subcarriers that is associated with pilot frequency code element the average noise variance of each in these pilot frequency code elements.System 1900 also comprises and being used at least in part based on the average noise variance of these pilot frequency code elements and the device of average frequency domain channel estimating generation pilot modulation error ratio.

The example that has comprised one or above embodiment described above.Certainly, be impossible for describing each combination that can contemplate that above-mentioned these embodiment describe assembly or method collection, but those of ordinary skills can recognize that it is possible that the many further combination of various embodiment and displacement are arranged.Correspondingly, described these embodiment are intended to contain spirit and all changes like this, the modification in the scope that drops on claims and are out of shape.In addition, with regard to term " comprise " originally specify or claims in regard to the category that uses, so term is intended to do and can furthermore separate " to comprise " the similar mode of being understood when being used as the transition speech in claim with term.

Claims (34)

1. one kind helps method that the transmitter performance of wireless communications environment is estimated, comprising:

Generate each the average frequency domain channel estimating on the unit data of transmitter signal in a plurality of subcarriers;

The pilot frequency code element noise of each that determine based on each described average frequency domain channel estimating of described a plurality of subcarriers to be associated with pilot frequency code element in described a plurality of subcarrier;

Determine the average noise variance of described pilot frequency code element at least in part based on each the described pilot frequency code element noise that is associated with described pilot frequency code element in described a plurality of subcarriers; And

Generate the pilot modulation error ratio of indication transmitter performance at least in part based on each described average frequency domain channel estimating of the described average noise variance of described pilot frequency code element and described a plurality of subcarriers.

2. the method for claim 1, it is characterized in that described pilot modulation error compares at following at least one generation: time division multiplexing 1 (TDM1) pilot frequency code element, wide area sign channel (WIC) pilot frequency code element, local sign channel (LIC) pilot frequency code element and time division multiplexing 2 (TDM2) pilot frequency code element.

3. the method for claim 1 is characterized in that, also comprises:

The described average noise variance of described pilot frequency code element is calibrated so that described pilot modulation error is than suitable with the Modulation Error Rate of data symbols.

4. the method for claim 1 is characterized in that, also comprises:

To from the analog signal sampling of transmitter to generate described transmitter signal; And

At since the caused power amplification non-linearity of analog signal of described transmitter of after power amplification, sampling described transmitter signal is proofreaied and correct.

5. the method for claim 1 is characterized in that, also comprises:

Determine in described a plurality of subcarrier the modulated symbol of each, described modulated symbol is used in and generates in the described average frequency domain channel estimating.

6. method as claimed in claim 5 is characterized in that, determines that the modulated symbol of each further comprises in described a plurality of subcarrier:

May modulated symbol determine in the corresponding point of described transmitter signal and the described complex plane in the complex plane and in described a plurality of subcarrier one corresponding to the distance between the point of possible modulated symbol at least one; And

Selection is corresponding to the most possible modulated symbol of the modulated symbol point of close described signaling point, and one modulated symbol is selected modulated symbol described in described a plurality of subcarriers.

7. the method for claim 1 is characterized in that, also comprises:

Before generating described average frequency domain channel estimating, earlier frequency domain channel is estimated execution of phase correction.

8. the method for claim 1 is characterized in that, described transmitter signal is forward link (FLO) signal only.

9. device that helps to estimate the transmitter performance in the wireless communications environment comprises:

Processor, it generates each the average frequency domain channel estimating on RF signal superframe in a plurality of subcarriers, the noise of definite each subcarrier that is associated with pilot frequency code element, determine the noise variance of described pilot frequency code element at least in part based on described average frequency domain channel estimating, and the pilot modulation error ratio that generates described pilot frequency code element at least in part based on the described noise variance of described pilot frequency code element; And

Be coupled to the memory of described processor, the information that its storage is relevant with described pilot frequency code element.

10. device as claimed in claim 9 is characterized in that, also comprises:

Signal analyzer, it is coupled to transmitter with the described RF signal of sampling.

11. device as claimed in claim 9 is characterized in that, described processor is determined in described a plurality of subcarrier the modulated symbol of each, and described modulated symbol is used in and generates in the described average frequency domain channel estimating.

12. device as claimed in claim 11, it is characterized in that, a plurality of zonings of described memory stores planisphere, each zoning is corresponding to a possibility modulated symbol, and described processor selects constellation point corresponding to described RF signal to be positioned at wherein zoning to each of described a plurality of subcarriers, and one modulated symbol is the possible modulated symbol of corresponding selected zoning described in described a plurality of subcarriers.

13. device as claimed in claim 9, it is characterized in that described processor generates described pilot modulation error ratio at following at least one: time division multiplexing 1 (TDM1) pilot frequency code element, wide area sign channel (WIC) pilot frequency code element, local sign channel (LIC) pilot frequency code element and time division multiplexing 2 (TDM2) pilot frequency code element.

14. device as claimed in claim 9 is characterized in that, described processor is calibrated the described average noise variance of described pilot frequency code element so that described pilot modulation error is than suitable with the Modulation Error Rate of data symbols.

15. device as claimed in claim 9 is characterized in that, described processor was estimated execution of phase correction to described frequency domain channel earlier before generating described average frequency domain channel estimating.

16. device as claimed in claim 9 is characterized in that, also comprises the display module that graphical user's interface (GUI) of the described pilot modulation error ratio of checking described pilot frequency code element is provided to the user.

17. a radio communication device comprises:

Be used for generating the device of each average frequency domain channel estimating on the unit data of transmitter signal of a plurality of subcarriers;

The device of the pilot frequency code element noise of each that is used for determining based on each described average frequency domain channel estimating of described a plurality of subcarriers that described a plurality of subcarrier is associated with pilot frequency code element;

The described pilot frequency code element noise of each that is used at least in part being associated with described pilot frequency code element based on described a plurality of subcarriers is determined the device of the average noise variance of described pilot frequency code element; And

Be used at least in part generating the device of the pilot modulation error ratio of indication transmitter performance based on each described average frequency domain channel estimating of the described average noise variance of described pilot frequency code element and described a plurality of subcarriers.

18. device as claimed in claim 17 is characterized in that, also comprises:

Be used for the described average noise variance of described pilot frequency code element is calibrated so that the described pilot modulation error ratio device suitable with the Modulation Error Rate of data symbols.

19. device as claimed in claim 17 is characterized in that, also comprises:

Be used for determining each the device of modulated symbol of described a plurality of subcarriers, described modulated symbol is used in and generates in the described average frequency domain channel estimating.

20. device as claimed in claim 19 is characterized in that, also comprises:

Be used for may modulated symbol determining in the corresponding point of described transmitter signal and the described complex plane in complex plane and the described a plurality of subcarrier one device corresponding to the distance between the point of possible modulated symbol at least one; And

Be used to select corresponding to the device of the possible modulated symbol of the modulated symbol point of close described signaling point, one modulated symbol is selected modulated symbol described in described a plurality of subcarriers.

21. device as claimed in claim 17 is characterized in that, also comprises:

Be used for before generating described average frequency domain channel estimating, earlier frequency domain channel being estimated the device of execution of phase correction.

22. device as claimed in claim 17, it is characterized in that described pilot tone is at least one in time division multiplexing 1 (TDM1) pilot frequency code element, wide area sign channel (WIC) pilot frequency code element, local sign channel (LIC) pilot frequency code element and time division multiplexing 2 (TDM2) pilot frequency code element.

23. the computer-readable medium with the computer program code that comprises instruction, described instruction is used for:

Generate each the average frequency domain channel estimating on the unit data of transmitter signal in a plurality of subcarriers;

The pilot frequency code element noise of each that determine based on each described average frequency domain channel estimating of described a plurality of subcarriers to be associated with pilot frequency code element in described a plurality of subcarrier;

Determine the average noise variance of described pilot frequency code element at least in part based on each the described pilot frequency code element noise that is associated with described pilot frequency code element in described a plurality of subcarriers; And

Generate the pilot modulation error ratio of indication transmitter performance at least in part based on each described average frequency domain channel estimating of the described average noise variance of described pilot frequency code element and described a plurality of subcarriers.

24. computer-readable medium as claimed in claim 23 is characterized in that, described program also comprises the instruction that is used for following action:

The described average noise variance of described pilot frequency code element is calibrated so that described pilot modulation error is than suitable with the Modulation Error Rate of data symbols.

25. computer-readable medium as claimed in claim 23 is characterized in that, described program also comprises the instruction that is used for following action:

Before generating described average frequency domain channel estimating, earlier frequency domain channel is estimated execution of phase correction.

26. computer-readable medium as claimed in claim 23 is characterized in that, described program also comprises the instruction that is used for following action:

Determine in described a plurality of subcarrier the modulated symbol of each, described modulated symbol is used in and generates in the described average frequency domain channel estimating.

27. computer-readable medium as claimed in claim 26 is characterized in that, the instruction of described definite modulated symbol also comprises:

May modulated symbol determine in the corresponding point of described transmitter signal and the described complex plane in the complex plane and in described a plurality of subcarrier one corresponding to the distance between the point of possible modulated symbol at least one; And

Selection is corresponding to the most possible modulated symbol of the modulated symbol point of close described signaling point, and one modulated symbol is selected modulated symbol described in described a plurality of subcarriers.

28. computer-readable medium as claimed in claim 23 is characterized in that, the instruction of described definite modulated symbol also comprises:

Generation is used for presenting to the user graphical user's interface (GUI) of described pilot modulation error ratio.

29. an execution is used for estimating the processor of instruction of the transmitter performance of wireless communications environment, described instruction comprises:

Generate each the average frequency domain channel estimating on the unit data of transmitter signal in a plurality of subcarriers;

The pilot frequency code element noise of each that determine based on each described average frequency domain channel estimating of described a plurality of subcarriers to be associated with pilot frequency code element in described a plurality of subcarrier;

Determine the average noise variance of described pilot frequency code element at least in part based on each the described pilot frequency code element noise that is associated with described pilot frequency code element in described a plurality of subcarriers; And

Generate the pilot modulation error ratio of indication transmitter performance at least in part based on each described average frequency domain channel estimating of the described average noise variance of described pilot frequency code element and described a plurality of subcarriers.

30. processor as claimed in claim 29 is characterized in that, described instruction also comprises:

The described average noise variance of described pilot frequency code element is calibrated so that described pilot modulation error is than suitable with the Modulation Error Rate of data symbols.

31. processor as claimed in claim 29 is characterized in that, described instruction also comprises:

Determine in described a plurality of subcarrier the modulation type of each, described modulated symbol is used in and generates in the described average frequency domain channel estimating.

32. processor as claimed in claim 31 is characterized in that, described instruction also comprises:

Modulation type is determined in majority voting based on the subclass that has consistent modulation type in described a plurality of subcarriers; And

Under the modulated symbol of this subcarrier and the inconsistent situation of described modulation type, reappraise its modulation type for each subcarrier in the described subclass of described a plurality of subcarriers.

33. processor as claimed in claim 29, it is characterized in that described pilot modulation error compares at following at least one generation: time division multiplexing 1 (TDM1) pilot frequency code element, wide area sign channel (WIC) pilot frequency code element, local sign channel (LIC) pilot frequency code element and time division multiplexing 2 (TDM2) pilot frequency code element.

34. processor as claimed in claim 29 is characterized in that, described instruction also comprises:

Before generating described average frequency domain channel estimating, earlier frequency domain channel is estimated execution of phase correction.

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