CN2757452Y - Route merging and correlator - Google Patents

Abstract

The utility model relates to a route merging and correlating device, wherein the route position information is separated by a separator according to pairity. Partial time delay units respectively carry out delayed time processing for training sequence code words to obtain a batch of data sequences; data sequences from partial time delay units respectively multiplied by channel estimation values of a corresponding route by a first multiplier; a batch of data sequenced from a part of the multiplier is added by a first adder element by element; a plurality of data at the tail part of the data sequences from the first adder are deleted by a deleter, and the data sequences are adjugated; a route separating device samples the receiving data which is input to corresponding training sequences, and the receiving data are separated according to the pairity; the data sequences from the route separating device are respectively multiplied by the adjugated data sequences by two second multipliers element by element; the two data sequences from the two second multipliers are added by a second adder element by element. The utility model can accurately realize the route merging and the route correlating in a time-division system under the condition of low SINR.

Description

A kind of path merges and correlator

Technical field

The utility model relates to a kind of path and merges and correlator, and particularly a kind of path in the automatic frequency correction of time-division (TimeDivision) wireless communication system receiver merges and correlator.

Background technology

In typical wireless communication system, owing to have frequency departure between the local oscillator (LocalOscillator) of transmitter and receiver, can cause the serious decline of received signal quality, even the communications failure.Particularly, for (the User Equipment of the user terminal in the cell mobile communication systems, UE), consideration for economic factor etc., the normal lower local oscillator of frequency stability that adopts, its original frequency deviation (Initial Frequency Offset) can reach about 10ppm, and this is equivalent to the original frequency deviation about 20kHz to the system that adopts the 2GHz carrier wave.If do not take the frequency output of corresponding measure correcting local oscillator, make its output frequency consistent or, the failure that may cause signal to transmit very near (for example, deviation is in 0.1ppm) with transmitter.On the other hand, because local oscillator is used to transmit and receive simultaneously, the serious band of generation disturbs (out-of-bandinterference) outward so big frequency departure can cause transmitting equally.In receiver, be used to realize that the device of Frequency Synchronization often is called as automatic frequency correction (Automatic Frequency Correction is called for short " AFC ") device.

General, when initial frequency departure is big, the situation when for example reaching 10ppm, automatic frequency correction can be divided into coarse frequency correcting (Coarse AFC) and fine frequency is proofreaied and correct (Fine AFC) two stages.This be because:

(1) receiver is in when start, often will pass through steps such as a series of time, frequency, sign indicating number and frame structure be synchronous, finishes synchronous and system's access function.And for different synchronous phases, desired received signal quality and the target that can reach also are inconsistent usually.That is some stage only needs rough Frequency Synchronization to get final product, and other stages then require more accurate Frequency Synchronization; On the other hand, some stage can only reach rough Frequency Synchronization according to the information that can utilize, and other stages are because the available information increase can realize more accurate Frequency Synchronization;

(2) for a key modules in the automatic frequency correction (AFC), be that frequency departure is estimated (Frequency Offset Estimation, be called for short " FOE ") module, weigh its performance and mainly contain two indexs: be i.e. frequency departure estimated accuracy and maximum frequency deviation estimation range.If the actual frequency deviation surpasses this scope, serious deviation just might take place in the output of FOE module so.And various FOE methods often have a common characteristic: promptly the precision of Gu Jiing is high more, and its maximum frequency deviation scope of supporting is also just more little; Otherwise if will support bigger frequency departure scope, then its estimated accuracy will reduce.When having relatively high expectations (for example 0.1ppm) for the bigger situation of original frequency deviation (for example 10ppm) and final frequency deviation, generally need to adopt different frequency offset estimation algorithm of two covers and corresponding AFC strategy thereof, finish coarse frequency correcting and fine frequency respectively and proofread and correct two processes.

General, from the transmitting of transmitter, regular meeting continuous or periodically have pilot tone (Pilot) or (SYNC) code word synchronously, they are known or by detected someway at the receiver place.So the AFC module can utilize these code words as training sequence (Training Sequence), after a series of processing of corresponding received signal process, finish the work of frequency correction.Although AFC also can carry out under the pattern of training sequence the unknown, promptly so-called " blind " be mode (blind), and its performance particularly is lower than under the 0dB situation generally relatively poor in signal to noise ratio, general less application in the existing wireless communications system.

(Time-Division) system was meant the communication frequency resource was divided into a plurality of time slots (Timeslot) by time shaft time-division, and each logic channel (Logical Channel) takies one or more time slot and transmits.Time-division system comprise time division multiple access (Time Division Multiple Access, TDMA) system and time division duplex (Time Division Duplex) system etc.It is GSM and TD-SCDMA that two covers adopt the example of the typical cellular mobile system of time division technique.In these systems, certain part of each time slot usually has one section synchronization code word or training sequence, be used to help the receiver deadline synchronously, functions such as Frequency Synchronization and channel estimating.On the other side is that those adopt frequency or code word to separate the system of Different Logic channel, for example IS-95 and WCDMA, in these systems, generally have continuous pilot transmitted channel (Pilot Channel), may adopt relatively more flexible way to finish a series of synchronizing functions based on this continuous pilot channel, comprise Frequency Synchronization function etc.

Some are in the designed AFC method of DS-SS cdma system (comprising IS-95 and WCDMA etc.), suppose to have the existence of continuous pilot signal, adopted phase difference detection (DifferentialDetection) or discrete Fourier transform (DFT) methods such as (Discrete Fourier Transform) to carry out Frequency offset estimation, and realized that in conjunction with the RAKE receiver structure multipath merges.For example, at International Patent Application Publication No. WO9931816, the utility model name is called among " a kind of method and apparatus that carries out frequency acquisition and tracking in the DS-CDMA receiver " (Method and Apparatus for Frequency Acquisitionand Tracing for DS-SS CDMA Receiver), a kind of AFC structure based on RAKE receiver is disclosed, and can adopt the variable-length relevant treatment to carry out the frequency departure estimation approach adaptively in the different AFC stage, can in the DS-SS cdma system, obtain preferable performance.

Yet, for time-division system, TD-SCDMA system for example, its pilot signal generally is discontinuous, and may should not adopt the RAKE receiver structure because it adopts Multiuser Detection (Multi-User Detection) method.Therefore, many at DS-SS cdma system design automatic frequency correcting method and be not suitable for the time division multiple access connecting system.In addition, different with arrowband time-division system (as GSM) in the past is, in broadband time-division system (for example TD-SCDMA system), Signal to Interference plus Noise Ratio (Signal-to-Interference-and-Noise Ratio on each chip (chip), be called for short " SINR ") very low, its representative value is lower than 0 dB.Therefore, just no longer suitable under this low SINR situation at some suitable AFC methods of arrowband time-division system in the past.Therefore, the AFC method and apparatus that design meets the demands at the broadband time-division system is one of key issue in these system designs.

For radio communication mobile communication system particularly, multipath fading be frequency diffusion (Frequency Dispersive) phenomenon to ubiquity in its propagation channel, can cause the SINR value of received signal bigger fluctuating can occur within a short period of time.On the other hand,, can life period spread (Time Dispersive) phenomenon again simultaneously, promptly produce serious intersymbol interference (Inter-Symbol Interference, ISI) problem for CDMA broadband communication systems such as (code division multiple accesss).Good receiver scheme at mobile communication system, must solve above two aspects problem---this is no exception for AFC Module Design in the receiver.

Often there are following one or several weak points in existing AFC method and apparatus at the time division communication system design:

(1) do not distinguish coarse frequency correcting and fine frequency and proofread and correct two processes, but adopt the unified AFC scheme of a cover: owing to above-mentioned reason, this scheme has often caused the contradiction between frequency departure estimation range and the frequency departure estimated accuracy, and/or the information that can utilize when failing effectively to utilize receiver to be in each stage.For example, route searching, tracking and channel estimation module generally just can obtain preferable performance after coarse frequency correcting is finished, and can be utilized by the fine frequency timing.On the other hand, in different phase, have different training sequences and can be used to the frequency departure correction.For example, at international monopoly WO0303040, the utility model name is called among " a kind of automatic frequency correcting method under the 3G radio communication TDD mode " (Automatic Frequency Correction Method and Apparatus for TimeDivision Duplex Modes of 3G Wireless Communications), a kind of method of carrying out frequency correction under 3G system time division duplex (TDD) pattern (HCR-TDD) is disclosed, but it is not distinguished coarse frequency correcting and fine frequency correction, but adopt the identical method and apparatus of a cover to realize frequency calibration function, and fail hour to utilize channel estimating and route searching in frequency deviation, the information of tracking module, thus therefore the convergence rate of its AFC loop is lost.

(2) ignored multipath fading (frequency diffusion) common in the radio communication channel to the influence that automatic frequency correcting method caused, perhaps ignored intersymbol interference (time diffusion) common in the broadband system influence that automatic frequency correcting method caused.For example, at United States Patent (USP) 2003099206, the utility model name is called among " automatic frequency correcting method and device " (Method and Arrangement for AutomaticFrequency Correction), frequency calibrating method under a kind of UTRA tdd mode is disclosed, but only having adopted the strongest propagation path to carry out frequency departure estimates, adopted the fixing AFC loop gain factor simultaneously, therefore performance can be received certain influence under the situation of decline and many strong propagation path existence fast, and its correction accuracy is also very limited.

Though the part automatic frequency correcting method also is divided into several stages with AFC, and adopt the different AFC loop gain factors to control convergence and the tracking performance of AFC under the different phase in each, but its AFC stage switches often and to judge by certain convergence and to carry out in stage.For example, adopt the mean value of recent Frequency offset estimation output valve to be used as the estimation of current frequency offseting value, and by comparing the switching judging criterion that is used as different phase with several thresholdings that set in advance (threshold) value.But, in these schemes, because the inaccuracy that convergence is judged, perhaps owing to needing the long period just can obtain convergence judgement comparatively accurately, so under the low signal-to-noise ratio condition, often need the long time to reach the convergence of AFC loop.On the other hand,, can not dynamically adjust, so the performance under some communication environment may be relatively poor according to actual channel condition because the relevant AFC parameter in these methods generally is to establish in advance.

The utility model content

The purpose of this utility model is to provide a kind of path to merge and correlator, thereby can under the low SINR condition, and communication channel life period diffusion and frequency spread condition under, quickly and accurately the local oscillator frequencies and the oscillator frequency in the transmitter of receiver are carried out synchronously.

For achieving the above object, the technical solution of the utility model is as follows:

A kind of path merges and correlator, and comprising: a splitter, a separator, two first adders, two cancellers, two are gripped device, some first multipliers, some delayers, two second multipliers, one second adder altogether, wherein:

Described separator will separate by parity from the path position information that path searcher module produces, and also separate according to the parity of path position simultaneously and with these path position upper signal channel estimated values;

Described a part of delayer obtains a collection of data sequence with training sequence code word delay process respectively, and the delay value of this delayer is determined by the odd positions path respectively;

Described a part of first multiplier will multiply each other with the channel estimation value of respective path respectively from a collection of data sequence of above-mentioned a part of delayer, obtain a collection of new data sequence;

Described one first adder will obtain a new data sequence after will pursuing the element addition from a collection of data sequence process of above-mentioned a part of first multiplier;

A described canceller will obtain a new data sequence from the data sequence of above-mentioned one first adder deletion afterbody plurality of data and through after gripping device altogether and gripping altogether, and its length equals the length of training sequence;

Described another part delayer through delay process, obtains a collection of data sequence with the training sequence code word, and the delay value of this delayer is determined by the even number location paths respectively;

Described another part first multiplier will multiply each other with the channel estimation value of respective path respectively from a collection of data sequence of above-mentioned another part delayer, obtain a collection of new data sequence;

Described another first adder will obtain a new data sequence after will pursuing the element addition from a collection of data sequence process of above-mentioned another part first multiplier;

Described another canceller will obtain a new data sequence after will gripping device altogether and grip altogether from the data sequence of above-mentioned another first adder deletion afterbody plurality of data and through another, and its length equals the length of training sequence;

Described splitter obtains two data sequences by the odd even sequence number after along separate routes with the signal sampling value of corresponding training sequence, and its length is equal to training sequence length;

Described two second multipliers respectively will be from the data sequence of above-mentioned splitter, and grips pursuing element respectively by the corresponding data sequence of odd even sequence number and multiplying each other of device altogether from above-mentioned, obtains two new data sequences;

Described one second adder will obtain a new data sequence as output after will pursuing the element addition from two sequences of described two second multipliers, and its length equals the length of training sequence.

Adopt said apparatus, can under very low SINR condition, realize exactly also that fast the path in the time-division system merges with relevant.Especially, the utility model under i.e. frequency diffusion and the time spread condition, can keep good performance at two kinds of common in the wide-band mobile communication system abominable channel conditions equally.

Description of drawings

Fig. 1 is for carrying out the structured flowchart that fine frequency is proofreaied and correct in the TD-SCDMA system;

Fig. 2 merges flow chart with relevant method for carry out a kind of path of carrying out in fine frequency trimming process as shown in Figure 1;

Fig. 3 merges structured flowchart with relevant device for the utility model carries out a kind of path of carrying out in fine frequency trimming process as shown in Figure 1;

Fig. 4 is for carrying out the flow chart of Kalman (Kalman) gain factor Calculation Method in fine frequency trimming process as shown in Figure 1; And

Fig. 5 is the implementation structure block diagram of the first-order loop filter in fine frequency correcting structure as shown in Figure 1.

Embodiment

According to Fig. 1 to Fig. 5, provide better embodiment of the utility model, and described in detail below, enable to understand better function of the present utility model, characteristics.

Fig. 1 carries out the structured flowchart that fine frequency is proofreaied and correct according to the utility model in the TD-SCDMA system.Described fine frequency trimming process is based on that Kalman (Kalman) filter theory realizes by a first-order loop.At first, received RF signal is through down-conversion demodulator 1010 and through being converted into digital baseband signal behind ADC, AGC and the RRC filter, follow the sampled data in the Midamble receiving unit that signal data extractor 1011 is 144 chips according to length in the last P-CCPCH channel of frame synchronization information extraction TS0, corresponding to 2 times of over-sampling situations, extracted 144 * 2=288 Midamble data sampling altogether.This segment data sampling plays an important role for system synchronization, will be used in channel estimating, route searching, SINR estimation and the frequency offset estimation module.Corresponding length is that 144 Midamble training sequence is produced by Midamble codeword generator 1012, and its codewords indexes is detected by the previous search of initial zone second step Step2.

Then, this section Midamble data sampling is admitted to channel estimating and path searcher module 1013.This module is relevant by Midamble data sampling and corresponding Midamble training sequence are carried out (circulation), obtains one group of channel estimation value.The average estimated channel power value that calculates in the present frame, constituted the time delay envelope (Delay Profile) of present frame, and route searching is according to the time delay envelope of present frame and in conjunction with the time delay envelope of former some frames, and according to some preset threshold value, in conjunction with current maximum path power and average noise power, judge which paths is an active path.Note owing to adopted 2 samplings, so the resolving accuracy in path is 1/2 chip width.Because channel estimating and route searching particularly mobile communication system extensive use of wireless communication system in each are so the relevant technologies personnel are very familiar to its related algorithm and implementation method in this area, so repeat no more here.Here channel estimating will be exported the amplitude and the phase value in all paths in so-called " channel estimation window ", for example, the channel estimating window width can be decided to be 16 chips, and corresponding to 2 times of over-samplings, common property is given birth to the amplitude and the phase value of 16 * 2=32 paths in this estimating window.Wherein, described every paths is represented a time delay tap (Delay Tap).Simultaneously, channel estimating also can be exported channel estimating all channel estimation values outside window in the correlation length, offers when module such as measurement is estimated parameter such as SINR to use.On the other hand, the path searcher module positional information of active path in the delivery channel estimating window then.Here suppose that path searcher module produces L bar active path positional information at most.Other module in the receiver comprises demodulation (Demodulation) module, synchronous (Synchronization) module and measurement (Measurement) module etc., will utilize these active path positional informations and channel estimation value to carry out relevant work.

With reference to figure 1, the path merges and correlator (module) 1014 utilizes described routing information and corresponding channel estimation value again, and the mode that merges (Maximum Ratio Combining is called for short " MRC ") by maximum ratio is carried out the merging of mulitpath.

Fig. 3 is the structured flowchart that carries out a kind of device of path merging according to the utility model in fine frequency trimming process as shown in Figure 1, and it adopts method as shown in Figure 2 to carry out the path merging with relevant:

(a) will separate by parity from the path position information that path searcher module produces; Simultaneously, these path position upper signal channel estimated values are also separated according to the parity of path position;

(b) with a collection of delayer of training sequence code word process, obtain a collection of data sequence, input step (c); Wherein the delay value of delayer is determined by the odd positions path respectively;

(c) a collection of data sequence that will import, the channel estimation value with respective path multiplies each other respectively, obtains a collection of new data sequence;

(d) will through by after the element addition, obtain a new data sequence by a collection of data sequence of step (c) gained;

(e) will through canceller deletion afterbody plurality of data, and through after gripping altogether, obtain a new data sequence by a data sequence of step (d) gained, its length equals the length of training sequence;

(f) with a collection of delayer of training sequence code word process, obtain a collection of data sequence; Wherein the delay value of delayer is determined by the even number location paths respectively;

(g) will be by a collection of data sequence input step (c) of step (f) gained, and behind the repeating step (c)～(e), obtain another new data sequence, its length equals the length of training sequence;

(h) signal sampling value that will receive corresponding training sequence obtains two data sequences by the odd even sequence number through behind the splitter, and its length is equal to training sequence length;

(i) will be by two data sequences of the corresponding odd even sequence number of step (h) gained, respectively with pursue element respectively by two data sequences of step (e) and step (g) and multiply each other, obtain two data sequences;

(i) will pursue the element addition by two sequences of step (i) gained after, the data sequence that obtains is as output, its length equals the length of training sequence.

According to said method, with reference to installation drawing shown in Figure 3, at first, input length is that 288 Midamble partly receives data sampling, passes through splitter 1200 and is divided into two long sequences of 144 that are by odd indexed and even number sequence number.Simultaneously, from channel estimating and the next common L paths positional information { T of path searcher module ₁, T ₂..., T _L(0=＜T _k＜=T _Max-1), is divided into two-way by parity, is designated as { T respectively through separator 1201 _{Odd, 1}, T _{Odd, 2}..., T _{Odd, L1}And { T _{Even, 1}, T _{Even, 2}..., T _{Even, L2}, wherein L1 and L2 are respectively the number that the position value is respectively the path of odd and even number.Accordingly, the channel estimation results { h of input _T1, h _T2..., h _TLAlso the parity according to the respective paths position be divided into two-way: { h _{Todd, 1}, h _{Todd, 2}..., h _{Todd, L1}And { h _{Teven, 1}, h _{Teven, 2}..., h _{Teven, L2}.Then, be that 144 Midamble input data are by a collection of delayer 1202 with length ₁-1202 _L1, and a collection of multiplier 1203 ₁-1203 _L1, and by adder 1206 ₁All after the addition, realize convolution (Convolution) process with odd positions path channel estimated sequence.Notice that delayer is for input time delay Control Parameter T here _k, will be the time-delay of input data

Individual data unit (symbol wherein

Expression rounds operation), and, make the dateout segment length be where necessary in head end and terminal zero padding

So that each circuit-switched data alignment.Like this, adder 1206 ₁Being output as length is Data sequence, through canceller 1207 ₁It is last to delete it After the individual data, remaining length is 144 data sequence; Then, this sequence is through gripping device 1208 altogether ₁After gripping altogether, by multiplier 1209 ₁Pursue element with the odd indexed data sampling of splitter 1200 output and multiply each other, obtain one group and estimate that by the odd positions path channel length that obtains is that 144 related data is exported.Similarly, by a collection of delayer 1204 ₁-1204 _L1, a collection of multiplier 1205 ₁-1205 _L1, an adder 1206 ₂, canceller 1207 ₂, grip device 1208 altogether ₂, and by multiplier 1209 ₂Pursue element with the even number sequence number data sampling of splitter 1200 output and multiply each other, can obtain another and organize corresponding even number position path channel and estimate that the length that obtains is that 144 related data is exported.At last, the related data that the corresponding respectively odd and even number location paths of described two-way channel estimating is obtained is by adder 1210 additions, just obtained length and be 144 relevant output result.

Then, with reference to figure 1, the Midamble after this batch merges through multipath receives data and is admitted to frequency offset estimator 1015 with Midamble code word that this locality produces, and the output frequency skew is estimated

It needs to be noted that multipath merging was here carried out before Frequency offset estimation.And in other many AFC method and apparatus, the two order is opposite often.For example European patent EP 1300962, the utility model name is called among " automatic frequency correcting device and automatic frequency correcting method " (Automatic Frequency Control Device and Automatic Frequency ControlMethod), Frequency offset estimation is at first carried out respectively on every paths, and then merges by maximum ratio merging mode.In the utility model, because merging, multipath before Frequency offset estimation, carries out, so only need carrying out a Frequency offset estimation, the utility model gets final product; According to the above-mentioned utility model of quoting then needs carry out repeatedly Frequency offset estimation, its number of times equates with number of path, so its complexity will exceed much than the complexity of the counter structure in the utility model.On the other hand, relevant emulation shows that these two kinds of performances that structure reached are very approaching.

With reference to figure 1, the routing information and the channel estimation results of channel estimating and path searcher module 1013 outputs are admitted in the SINR estimator module 1016, produce present frame SINR estimated value.This SINR estimator also is based on TSO and goes up the SINR estimated value that Midamble sign indicating number in the P-CCPCH channel obtains present frame.

Then, with reference to figure 1, Kalman (Kalman) gain factor calculator 1017 utilizes the SINR of present frame to estimate, carries out the renewal of described first-order loop gain factor.Institute's updated parameters comprises: measure noise variance R _k, estimate variance P _kWith Kalman Kalman gain factor K _k, wherein subscript k represents the sequence number of present frame.

Figure 4 shows that the flow chart that in fine frequency trimming process as shown in Figure 1, carries out kalman gain factor Calculation Method according to the utility model.(promptly enter before the fine frequency trimming process) under the initial condition, in step 1501, P ₀Be endowed an initial value, general, P ₀Should be provided with according to the variance that enters fine frequency correction frequency deviation before.According to the utility model, P ₀Should determine that recommendation is P according to the variance of the output frequency deviation of coarse frequency correcting _n=(2000) ²In addition, P ₀Also can determine according to the SINR value of being surveyed at that time.

Next, the fine frequency means for correcting is started working, and in step 1502, the initial value of frame counter k is made as 1.Then in step 1503, the frequency offset estimating variance R of present frame _kWill be based on the SINR estimated value SINR of present frame _kCalculate, concrete computing formula is:

$R_k=K_R\×\frac{1}{{\mathrm{RINR}}_k}$

This formula obtains at the TD-SCDMA system according to improved Wayne Kramer-La Ao (Cramer-Rao) boundary.Wherein, according to Wayne Kramer-La Ao circle, constant K _RValue should determine according to relevant system parameters:

$K_R=\frac{3}{{2\mathrm{\π}}^2{T}_c^2}\·\frac{1}{N(N^2-1)}$

Wherein, T _cRepresented system's chip width, and N has represented the length of used training data sequence.For TD-SCDMA system, 1/T _c=1.28Mcps, and the length N of used Midamble code word=144 can get K in view of the above _R=(288.8) ²The specifying information of relevant improved Wayne Kramer-La Ao circle, can be outstanding with reference to peace people such as (A.N.D ' Andrea) delivered on the IEEE Transaction on Communication magazine in 1994, name is called the paper of " The Modified Cramer-Rao Bound and Its Applications toSynchronization Parameters ", and one of ordinary skill in the art is easy to grasp.

Follow in step 1504 the kalman gain factor K _kR by present frame calculating _kP with former frame calculating _K-1Try to achieve, according to kalman filtering theory, calculating K _kFormula be:

K _k＝P _k-1(P _k-1+R _k) ^-1

Then in step 1505, judge the K that is calculated _kWhether value is less than a preset value K _LOWIf, K _k＜K _LOW, then enter step 1507, change K _kMake it equal K _LOW, with seasonal P _k=P _K-1Otherwise, if K _k＞=K _LOW, then enter step 1506, according to kalman filtering theory, calculate by present frame

The K of gained _kValue and former frame calculate P _K-1Value is calculated P _kValue:

P _k＝(1-K _k)P _k-1

Here, to K _kThe purpose of following amplitude limit is: when loop gain is too small, be difficult to follow the tracks of very fast frequency drift; Therefore, need be to loop gain K _kFollowing amplitude limit is to guarantee to follow the tracks of the upper frequency skew.The Lower Limit Amplitude K that recommends _LOWBe 1/64 or 1/128-K _LOWPreferred value should determine by specific implementation and operational environment.

Then, in step 1508, the output kalman gain factor K that present frame calculated _kTo loop filter.Then in step 1509, frame counter k adds 1, prepares to carry out having in the next frame renewal of related parameter.

Then, with reference to figure 1, first-order loop filter 1018 will be according to input (Frequency offset estimation that present frame calculates) and K _k(the Kalman Kalman gain factor that present frame calculates) carries out first-order filtering, and the Frequency offset estimation value that adds up of output present frame

With reference to figure 5, be depicted as implementation structure block diagram according to the first-order loop filter of the utility model in fine frequency correcting structure as shown in Figure 1.Wherein, input

At first with the kalman gain factor K _kMultiply each other by a multiplier 161, then with former frame in output

By adder 162 additions, obtain output and can be represented by the formula:

${\hat{f}}_k={\hat{f}}_{k-1}+K_k\mathrm{\Δ}{\hat{f}}_k$

The effect of delayer 163 is the output of preserving present frame

And feedback is used in next frame.

In addition, as a kind of simplification, also can be fixed as loop gain among several particular values, for example { 1.0,0.5,0.1,0.05,0.01} gets the output K of the most approaching above-mentioned kalman gain factor calculator in this set then _kThat value, as present frame control loop yield value.Can simplify relevant operation like this, performance does not have big loss simultaneously.

At last, with reference to figure 1, the output of first-order loop filter 1018 is converted into control voltage according to the voltage-controlled characteristic of local oscillator 1019, and controls local voltage controlled oscillator 1019 through DAC, thereby has finished the fine frequency trimming process in the present frame.In next frame, above-mentioned fine frequency trimming process will repeat.Like this, along with the increase of handling frame number, the output of loop filter control constantly obtains upgrading, and makes 1019 outgoing carrier frequency of local oscillator

Constantly approach the practical carrier frequency f of input signal _k, and making difference between them, promptly residual frequency offseting value reaches the desired value (for example, the 0.1ppm of standard defined or lower) that guarantees other module operate as normal in the receiver.

So far, described a kind of preferred forms of the present utility model in conjunction with the accompanying drawings in detail.Those of ordinary skill in the art should recognize, here be used to describe various logical units of the present utility model, module, circuit and algorithm steps etc., can adopt electronic hardware (electronic hardware), computer software (computer software) or their combination to put into effect.Here all being to describe according to their function usually to various elements, unit, module, circuit and step, adopting hardware or software during realization actually, is that concrete application and the design constraint by whole system decides.Those of ordinary skill in the art should recognize the interchangeability of hardware and software under specific circumstances, and can adopt best mode to realize that the described class of the utility model carries out the path and merge and relevant device in the automatic frequency correction of receiver of time-division wireless communication system at concrete application.

For example, here be used to describe various logical units of the present utility model, module, circuit and algorithm steps etc., can be in the following ways or their combination realize, comprising: digital signal processor (DSP), special purpose integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device, (discrete) gate (gate) or transistor (transistor) logic of separating, the hardware component (for example register and FIFO) that separates, carry out the processor of a series of firmwares (firmware) instruction, traditional programming software (programmable software) and relevant processor (processor) etc.Wherein, processor can be microprocessor (microprocessor), also can be traditional processor, controller (controller), microcontroller (microcontroller) or state machine (state machine) etc.; Software module can be present in RAM memory, flash memory (flash memory), ROM memory, eprom memory, eeprom memory, register, hard disk, moveable magnetic disc, CD-ROM or any existing known storage medium.

The obviously clear and understanding of those of ordinary skill in the art, the most preferred embodiment that the utility model is lifted is only in order to explanation the utility model, and be not limited to the utility model, the utility model for the technical characterictic among each embodiment, can combination in any, and do not break away from thought of the present utility model.Merge and relevant device according to the disclosed a kind of path of in the automatic frequency correction of receiver of time-division wireless communication system, carrying out of the utility model, can there be many modes to revise disclosed utility model, and except the above-mentioned optimal way that specifically provides, the utility model can also have other many embodiment.Therefore, all genus all should be included within the interest field of the present utility model according to the utility model design getable method of institute or improvement.Interest field of the present utility model is defined by the following claims.

Claims (1)

1, a kind of path merges and correlator, and comprising: a splitter, a separator, two first adders, two cancellers, two are gripped device, some first multipliers, some delayers, two second multipliers, one second adder altogether, it is characterized in that:

Described separator receives path position information and the path position upper signal channel estimated value that produces from path searcher module, separates by parity;

Described a part of delayer received training sequence code word is exported a collection of data sequence, and the delay value of this delayer is determined by the odd positions path respectively;

Described a part of first multiplier receives a collection of data sequence of above-mentioned a part of delayer, and the channel estimation value with respective path multiplies each other respectively, exports a collection of new data sequence;

Described one first adder receives a collection of data sequence of above-mentioned a part of first multiplier, through by after the element addition, exports a new data sequence;

A described canceller receives the data sequence of above-mentioned one first adder, and deletion afterbody plurality of data and through after gripping device altogether and gripping is altogether exported a new data sequence, and its length equals the length of training sequence;

Described another part delayer received training sequence code word is exported a collection of data sequence, and the delay value of this delayer is determined by the even number location paths respectively;

Described another part first multiplier receives a collection of data sequence of above-mentioned another part delayer, and the channel estimation value with respective path multiplies each other respectively, exports a collection of new data sequence;

Described another first adder receives a collection of data sequence of above-mentioned another part first multiplier, through by after the element addition, exports a new data sequence;

Described another canceller receives the data sequence of above-mentioned another first adder, deletion afterbody plurality of data and grip device altogether and grip altogether through another after, export a new data sequence, its length equals the length of training sequence;

Described splitter receives the signal sampling value of corresponding training sequence, exports two data sequences in the back along separate routes by the odd even sequence number, and its length is equal to training sequence length;

Described two second multipliers receive the data sequence of above-mentioned splitter respectively, and grip pursuing element respectively by the corresponding data sequence of odd even sequence number and multiplying each other of device altogether from above-mentioned, export two new data sequences;

Described one second adder receives two sequences of described two second multipliers, pursue the element addition after, export a new data sequence, its length equals the length of training sequence.

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