CN100539557C - Apparatus and method for predicting channel impulse response in global system for mobile communication - Google Patents
Apparatus and method for predicting channel impulse response in global system for mobile communication Download PDFInfo
- Publication number
- CN100539557C CN100539557C CNB2004100857745A CN200410085774A CN100539557C CN 100539557 C CN100539557 C CN 100539557C CN B2004100857745 A CNB2004100857745 A CN B2004100857745A CN 200410085774 A CN200410085774 A CN 200410085774A CN 100539557 C CN100539557 C CN 100539557C
- Authority
- CN
- China
- Prior art keywords
- symbol
- correlation
- value
- cross
- predetermined
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000004044 response Effects 0.000 title claims abstract description 69
- 238000000034 method Methods 0.000 title claims abstract description 42
- 238000010295 mobile communication Methods 0.000 title claims description 11
- 238000012549 training Methods 0.000 claims abstract description 39
- 238000004891 communication Methods 0.000 claims abstract description 24
- 238000005070 sampling Methods 0.000 claims abstract description 20
- 238000004088 simulation Methods 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 238000005562 fading Methods 0.000 abstract description 17
- 238000005516 engineering process Methods 0.000 description 10
- 230000005540 biological transmission Effects 0.000 description 7
- 238000004364 calculation method Methods 0.000 description 6
- 230000033228 biological regulation Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000012467 final product Substances 0.000 description 3
- 238000007476 Maximum Likelihood Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 230000010363 phase shift Effects 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000004422 calculation algorithm Methods 0.000 description 1
- 230000021615 conjugation Effects 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
Images
Landscapes
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
一种在通信系统中预测信道脉冲响应的方法。包含将所接收无线模拟信号转换成基频数字信号后，根据符号周期或比特周期产生的时间将该基频数字信号取样，再将多组所得至少部份取样与一组预定训练串符号进行互相关运算；互相关运算所得结果具有多峰值时，计算其中绝对值平方最大值及次大值的比值：若此值大于第一预定值，判断所接收的信号是经由AWGN信道传输，以该最大值的时间步骤索引及其相邻时间步骤索引的互相关值作为信道脉冲响应；若该比值不大于第一预定值，判断所接收信号是经由衰落信道传输，利用互相关运算结果计算预定长度区间能量，以使该预定长度区间能量为最大起始的时间步骤索引及其后继时间步骤索引的互相关值作为信道脉冲响应。
A method for predicting channel impulse response in a communication system. The method comprises converting a received wireless analog signal into a baseband digital signal, sampling the baseband digital signal according to the time when a symbol period or a bit period is generated, and then performing a cross-correlation operation on multiple groups of at least part of the samples and a group of predetermined training string symbols; when the result of the cross-correlation operation has multiple peaks, calculating the ratio of the maximum and the second largest square absolute value: if this value is greater than a first predetermined value, it is determined that the received signal is transmitted via an AWGN channel, and the cross-correlation value of the time step index of the maximum value and its adjacent time step index is used as the channel impulse response; if the ratio is not greater than the first predetermined value, it is determined that the received signal is transmitted via a fading channel, and the energy of a predetermined length interval is calculated using the result of the cross-correlation operation, so that the energy of the predetermined length interval is the cross-correlation value of the maximum starting time step index and its subsequent time step index as the channel impulse response.
Description
Technical field
The present invention relates to the device and method of a predicted channel impulse response, particularly a kind of at global system for mobile communications (global system for mobile communications, GSM) device and method of middle predicted channel impulse response.
Background technology
In mobile communication system, along with the raising of transmission rate and the upgrading of modulation technique, intersymbol interference (the Inter-SymbolInterference that is caused because of multipath propagation (multi-path propagation), ISI) heal and become serious, formed one of serious puzzlement of digital communication system.The decline that multipath propagation caused (fading) is a kind of because the phenomenon that radio wave is caused via refraction of different paths or reflection in transmission course.The signal that transmission ends transmitted arrives receiving terminal through different paths, and these signals through different paths will have different time delays and decay, the signal that different time transmitted before and after also therefore can having influence on, and cause the signal interference.The distortion that causes when propagating in channel for these signals, in communication system, the characteristic that receiver must can predicted channel and suitably compensated with balanced (equalization) technology is to reduce original signal.For the compensation of channel distortion, normally assess its usefulness with the accuracy of channel estimating.For by additivity white Gauss noise (additive white Gaussian noise, AWGN) and the digital signal destroyed of intersymbol interference, Maximum likelihood sequence equilibrium (maximum-likelihood sequenceequalization, MLSE) be the best balancing technique of widely being familiar with known to the digital technology person, for example as US Patent No.:6,459,728 " Iterative Channel Esti nmation " have promptly narrated a channel prediction method according to the realization of MLSE principle.Yet, in the mobile communication system of major part, because relatively moving between travelling carriage (mobile station) and surrounding environment, (channel impulse response CIR) is to become in time and is unknown to calculate the required channel impulse response of maximum possible sequencal estimation.Therefore, be the equilibrium and the trace routine of receiver, the parameter of predicted channel impulse response becomes primary affair.Generally speaking, (global systemfor mobile communications, GSM) in the receiver, channel impulse response is that the known training string (training sequence) that is used in after transmitting in the channel is predicted in global system for mobile communications.
Summary of the invention
Therefore, the present invention proposes a kind of method of predicted channel impulse response in wireless communication system, utilize training string and the signal of being received to carry out square (the being power) maximum of absolute value of computing cross-correlation gained and the ratio of second largest value is compared with a predetermined value, judge that as one channel is the mechanism of awgn channel or fading channel (fading channel), determine to carry out the squared absolute value maximum of the value of computing cross-correlation gained again according to the result who judges, or the energy in a predetermined length interval comes predicted channel impulse response according to training string and the signal of being received.Like this then can make receiver in two kinds of different channels, all can be with best algorithm predicts channel impulse response, and best channel equalization usefulness, take into account and save cost and amount of calculation and system effectiveness, to overcome the problem in the above-mentioned known technology.
According to the present invention, it is the method that discloses a kind of predicted channel impulse response in wireless communication system, after it comprises the wireless simulation conversion of signals that will be received and becomes the fundamental frequency digital signal, this fundamental frequency digital signal is taken a sample, will organize at least partly sampling of gained more again and carry out cross-correlation (cross-correlation) computing with one group of training string symbol (trainingsequence symbols) of being scheduled to according to the time of symbol period (symbol period) or bit period (bit period) generation; Calculate square maximum of absolute value among the result of computing cross-correlation gained in the above-mentioned steps and the ratio of second largest value: if this ratio is greater than one first predetermined value, then the cross correlation value that is not less than 2 time step index with this peaked time step index and neighbor distance thereof as channel impulse response (channel impulse response, CIR); And if this ratio is not more than this first predetermined value, then utilizing this computing cross-correlation result to calculate the energy in a predetermined length interval, is that the cross correlation value of the initial time step index of maximum and follow-up time step index thereof is as channel impulse response with the energy in this predetermined length interval.
According to the present invention, other discloses a kind of receiver in wireless communication system, and it comprises: an internal memory is used for storing one group of predetermined training string symbol (training sequence symbols); One cross-correlator (cross-correlator) is electrically connected to this internal memory, is used for sampling and this group training string symbol of received symbol are carried out a default computing cross-correlation; One peak value ratio comparator is electrically connected to this cross-correlator, is used for relatively square maximum of the absolute value of this computing cross-correlation and the ratio and one first predetermined value of second largest value; One calculates the value module on correlation peak both sides, be electrically connected to this peak value ratio comparator, be used in this ratio during, with the cross correlation value of this peaked time step index and adjacent time step index thereof, as channel impulse response and export it greater than this first predetermined value; And N correlation module of the N of a calculating energy maximum correlation module calculating energy maximum, be electrically connected to this peak value ratio comparator, be used for when this ratio is not more than this first predetermined value, to calculate the energy in a predetermined length interval by the output of this computing cross-correlation device, so that the energy in this predetermined length interval is the cross correlation value of maximum initial time step index and follow-up time step index thereof, as channel impulse response and export it.
Description of drawings
Fig. 1 is the calcspar of the wireless communication system receiver of known technology.
The calcspar of the wireless communication system receiver that Fig. 2 is proposed for Hyoung-kyu Song.
Fig. 3 is the calcspar of wireless communication system receiver of the present invention.
Fig. 4 is the flow chart of wireless communication system receiver predicted channel of the present invention impulse response.
The reference numeral explanation
10,20, the 30-wireless communication receiver
12,22, the 32-cross-correlator
13,23,33-trains string symbol
The interval energy calculator of 26-
34-peak value ratio comparator
35-calculates and exports the value module on correlation peak both sides
36-calculates and exports N correlation module of energy maximum
The 37-peak counter
Embodiment
General hypothesis Guassian Minimum Shift Keying GMSK (Gaussian minimum shift keying, GMSK) linear approximation is in Quadrature Phase Shift Keying (quadrature phase shift keying, QPSK) system, therefore we can one comprise the Channel Models of the QPSK system of a Gaussian filter as gsm system, and its corresponding channel coefficients can get via the cross-correlation (cross-correlation) of the known training string symbol of the output of calculating channel and receiver.This type of utilizes known training string symbol to find out channel impulse response has a variety of with the method for carrying out channel estimating, different modes predicted channel impulse responses such as the peak value of utilization as search cross-correlation or calculating energy respectively, it is respectively delivered on patent document or academic journal.About the principle of utilizing known training string to find out channel impulse response is to be employed training string in the digital communication system, often be designed to have the autocorrelation and the approximate incoherent white noise (uncorrelated white noise) of height, therefore after the time calibration of received symbol, peak value can appear in its cross-correlation with the training string.See also Fig. 1.Fig. 1 is the calcspar of a wireless communication system receiver.10 is a wireless communication receiver, and it includes a cross-correlator (cross-correlator) 12 and a training string symbol (training sequence symbol) 13, and training string symbol 13 is to be electrically connected to cross-correlator 12.In Fig. 1,
Be the quadruple sampling of received signal, meaning is to be cycle 1/4th long of the bit received of receiver or symbol in its cycle, x
kBe the quadruple sampling of training string originally, k is the index (time step index) of time step, and the length that makes L representative training string.As shown in Figure 1, we are with x
kAnd
Send into and carry out computing cross-correlation in the cross-correlator 12, the quadruple sampling of wherein received signal
Should comprise training string quadruple sampling x
kParagraph.So, then the output of cross-correlator 12 can be expressed as:
In the formula (1)
Be x
L-iMany conjugation.
Train the position of going here and there in the signal that is received in order to want to detect,
Length should compare x
kLong.In the known technology, have directly so that
The absolute value that is the output of cross-correlator 12 is the starting point of the pairing received sample of signal of maximum k value as the training string in the signal of being received, and the dopester of delivery channel impulse response.Yet because the Shi Bianyu of GSM channel decline characteristics such as (fading), for different bursts (burst), the position of the absolute value peak value of cross-correlation does not also mean that the position that training is gone here and there.Therefore, directly (promptly make with the time step index of the absolute value peak value of cross-correlation
Be peaked k) as the starting point of training string, be very may error take place and the demand that can't satisfy channel equalization.
See also Fig. 2.Fig. 2 is the calcspar of a wireless communication system receiver.20 is a wireless communication receiver, it includes a cross-correlator 22, one training string symbol 23 is electrically connected to cross-correlator 22, and one interval energy calculator 26 be used for calculating the energy in a predetermined length interval with the output of computing cross-correlation device 22, and so that the energy in this predetermined length interval is the cross correlation value of maximum zero-time step index and follow-up time step index thereof, as channel impulse response and export it.Wherein cross-correlator 22 is identical with the function of training string symbol 13 with the cross-correlator 12 among Fig. 1 with training string symbol 23;
x
k, k, L and cross-correlator output
Definition and intension, also identical with the technology of the described Fig. 1 of epimere.Interval energy calculator 26 can be calculated the energy in the predetermined length interval, makes the interval NT of being of this predetermined length, and then the energy in the predetermined length interval is:
Wherein N is the number of the coefficient of the channel impulse response of prediction, and i then is initial time step index.
In receiver as Fig. 2, promptly so that
For peaked i value φ pairing
As the starting point of the training string in the signal of being received, and the prediction of delivery channel impulse response
Energy with the predetermined length interval described above is as the technology of predicted channel impulse response, and because of calculate its energy in addition after cross-correlation, amount of calculation is more only carried out cross-correlation for big; So it has improved the problem that channel impulse response skew will take place and can't directly train the starting point of string with the absolute value peak value prediction of cross-correlation when the channel of transmission signals is fading channel (fading channel).Yet if when the channel of transmission signals is non-when being fading channel but awgn channel, calculating energy will lower the usefulness of system greatly with predicted channel impulse response.Though, in fact will train string and the absolute value peak value that the signal of being received carries out the value of computing cross-correlation gained to change because of these noises because the noise in the awgn channel can influence whole energy.Therefore if the known technology that only uses Fig. 2 and lifted comes calculating energy with predicted channel impulse response, the system that makes is increased on time of cost and amount of calculation, thereby need design than complicated hardware, pay higher cost.
See also Fig. 3.Fig. 3 is the calcspar of wireless communication system receiver of the present invention.30 is a wireless communication receiver, and it includes a cross-correlator 32; One training string symbol 33 is electrically connected to cross-correlator 32; One peak counter 37 is electrically connected to cross-correlator 32, is used for calculating the peak value number n of cross-correlator 32 operation results; One peak value ratio comparator 34 is electrically connected to peak counter 37, the peak value number n that is used for being calculated in peak counter 37 is for for a long time, calculates the ratio A0 of square maximum of absolute value of cross-correlator 32 operation results and second largest value and it is compared with one first predetermined value A1; One module 35 of calculating and export the value on correlation peak both sides is electrically connected to peak counter 37 and peak value ratio comparator 34, as A0 during greater than the first predetermined value A1 and when the peak value number is 1, with the cross correlation value of this peaked time step index and adjacent time step index thereof, as channel impulse response and export it; And one calculate and N correlation module 36 of output energy maximum, be electrically connected to peak value ratio comparator 34, when A0 is not more than the first predetermined value A1, to calculate the energy in a predetermined length interval by the output of computing cross-correlation device 32, so that the energy in this predetermined length interval is the cross correlation value of maximum initial time step index and follow-up time step index thereof, as channel impulse response and export it.Wherein, calculate and the function of N correlation module 36 of output energy maximum then identical with interval energy calculator 26;
Be the sampling of received signal, in true (simulation) experiment of walking back and forth of the present invention, we find with overclocking sampling (over sample)
The usefulness of carrying out computing does not significantly strengthen, and therefore in the present embodiment, directly the bit of being received with receiver or the Cycle Length of symbol are taken a sample to received signal, and meaning promptly
Sampling frequency be bit or symbol frequency; x
kBe training string originally, k is the index (time step index) of time step, and the length that makes L representative training string; Similarly, train the position of going here and there in the signal that is received in order to want to detect,
Length should compare x
kLong and should comprise x
kParagraph.The output of cross-correlator 32
Definition and intension, then identical with the described technology contents of Fig. 2.In of the present invention other used,
Still can be the integer multiple frequency sampling of received signal, x
kAlso relatively selling frequency sample for this integer of training string gets final product; Again
Or can be part in the integer multiple frequency sampling of received signal, for example for getting one in per two quadruples sampling, and x
kFor the relative sampling in the training string gets final product.
As previously mentioned, when signal when awgn channel transmits, the AWGN noise can influence received energy, but can not change cross-correlator 32 operation results absolute value square the position that peak value occurred; Therefore utilize the position of this peak value to get final product predicted channel impulse response.If signal is via fading channel transmission, then computing cross-correlation result's absolute value square the position that occurs of peak value can be offset,, should determine by which cross correlation value as predicted channel impulse response with the energy in a regular length interval.Therefore use the method for the ratio of square peak-peak of computing cross-correlation result's absolute value and time big peak value relatively among the present invention, judge and export the computing cross-correlation result in which way as channel impulse response.Square ratio A0 of computing cross-correlation result's absolute value is during greater than one first predetermined value A1, that is maximum goes out greatly when many than second largest value, and our channel of decision signal institute warp is an awgn channel; This moment, the value module 35 of calculating and exporting the correlation peak both sides sent into the output of cross-correlator 32 by peak value ratio comparator 34, the computing cross-correlation result of square peaked time step index of the absolute value that cross-correlator 32 is exported and adjacent time step index thereof is as channel impulse response and export it.Otherwise when the ratio A0 of square maximum of computing cross-correlation result's absolute value and second largest value is not more than this first predetermined value A1, that is maximum is not when going out abundant multiple greatly than second largest value, and our channel of decision signal institute warp is a fading channel; This moment, N the correlation module module 36 of calculating and exporting the energy maximum sent into the output of cross-correlator 32 by peak value ratio comparator 34, N correlation module 36 calculating and export the energy maximum will be as the energy in the calculating one predetermined length interval as the interval energy calculator 26 among Fig. 2, make the interval NT of being of this predetermined length equally, so that the energy in this predetermined length interval is the cross correlation value of maximum initial time step index and follow-up time step index thereof, as channel impulse response and export it.Wherein, rule of thumb, this first predetermined value A1 can be made as 8 with preferable, and so it also can be made as other value under varying environment and system requirements.Calculate and the value module 35 on output correlation peak both sides and the output of calculating and exporting N correlation module 36 of energy maximum
With
As follows respectively:
Wherein γ is for making
Value be maximum k value, k is a time step index.
Calculate and channel impulse response that the value module 35 on output correlation peak both sides is predicted for
Be the center, the both sides, front and back are symmetry respectively.Characteristic according to the GMSK modulation, its can be approximately pulse amplitude modulation (Pulse Amplitude Modulation, PAM), and the employed training string of gsm system just is being the GMSK modulation signal, therefore its channel impulse response is bell symmetry in low noise environment, thus can with
Be the center, it is exported as channel impulse response in both sides, the front and back output of the cross-correlation of symmetry respectively.In the present embodiment, for cooperating the relevant regulations of gsm system, can
Be the center, the both sides, front and back are respectively got the output of two cross-correlation respectively, promptly
Export it as channel impulse response.The present invention in other is used, but also the relevant regulations of coupled system and need and before and after getting the output of symmetry three or other quantity cross-correlation export it as channel impulse response.
Wherein φ is for making
Be peaked k value, and N is the number of the coefficient of the channel impulse response of prediction, k then is initial time step index.
Calculate and the prediction of the channel impulse response that N correlation module 36 of output energy maximum exported, identical with the output of the interval energy calculator 26 of prior art among Fig. 2; Promptly with
As the starting point of channel impulse response, get four points (because of the output of the prediction of establishing channel impulse response in the present embodiment needs totally five points) more backward, be
In like manner, the present invention is in other is used, but the also relevant regulations of coupled system and need and get
And thereafter six or the output of other quantity cross-correlation export it as channel impulse response.
The above is a content of the present invention.Be illustrated more clearly in the flow process that the present invention carries out the channel impulse response prediction for asking, see also Fig. 4.Fig. 4 is the flow chart of the receiver predicted channel impulse response of wireless communication system of the present invention.
Step 100: beginning channel impulse response prediction;
Step 110: the computing cross-correlation that the sampling of the sampling of the training string that stores in the internal memory and received signal is carried out pre-determined number;
Step 115: calculate the number n of peak value, if n is 1 execution in step 140; If n is greater than 1 execution in step 120;
Step 120: the ratio A0 of the maximum of squared absolute value and second largest value in the computing cross-correlation of this pre-determined number in the calculation procedure 110;
Step 130: compare an A0 and a predetermined value A1; As A0 greater than A1 execution in step 140 then; Be not more than then execution in step 150 of A1 as A0;
Step 140: be judged as awgn channel, as channel impulse response and export it, execution in step 160 again with square peaked index of the absolute value of computing cross-correlation result in the step 110 and each predetermined quantity y cross correlation value of front and back thereof;
Step 150: be judged as fading channel, with the computing cross-correlation result's of gained in the step 110 absolute value square, a predetermined quantity n adds up, calculating the energy in a predetermined length interval so that the energy in this predetermined length interval for maximum initial index and afterwards 2y cross correlation value as channel impulse response and export it;
Step 160: finish the channel impulse response prediction.
Combine it, the invention provides a device and method that is applicable to through the mobile communication system predicted channel impulse response of AWGN and fading channel transmission signals, and the present invention is specially adapted to use the receiver of the global system for mobile communications of maximum possible sequence balancing technique (MLSE).In the present invention, the characteristic of awgn channel and fading channel all is included into and considers, and judges how to export cross correlation value as channel impulse response with a simple method.The invention enables when judging that signal is when awgn channel transmits, directly with the peak value predicted channel impulse response of computing cross-correlation, receiver neither need expend huge amount of calculation calculating energy, the balanced usefulness that can obtain again; And when judging that signal is when fading channel is transmitted, in the mode of computation interval energy, accurately predicted channel impulse response.The present invention is with succinct framework and small amount of calculation, utilize known channel impulse response Predicting Technique, add relatively square maximum of computing cross-correlation result's absolute value and the step of a ratio between second largest value and a predetermined value, judge that as one channel is the mechanism of awgn channel or fading channel (fading channel), comply with the result of its judgement again, select the pairing preferable channel impulse response Forecasting Methodology of this kind channel, use receiver of the present invention in awgn channel or fading channel no matter make, all accurately predicted channel impulse response reaches best channel equalization usefulness.
The above only is preferred embodiment of the present invention, and all equalizations of being done according to the present patent application claim change and modify, and all should belong to the covering scope of patent of the present invention.
Claims (29)
1. the method for a predicted channel impulse response in wireless communication system comprises:
(a) the wireless simulation conversion of signals that is received is become the fundamental frequency digital signal after, this fundamental frequency digital signal is taken a sample, will organize at least partly sampling of gained more again and carry out computing cross-correlation with one group of training string symbol of being scheduled to according to the time of symbol period or bit period generation; And
(b) if having a plurality of peak values in this operation result, then calculate square maximum of absolute value in this operation result and the ratio of second largest value; And
(c) if this ratio greater than one first predetermined value, then gets peaked time step index and neighbor distance thereof with this computing cross-correlation and is not less than the cross correlation value of 2 time step index as channel impulse response.
2. the method for claim 1, it comprises in addition:
(d) calculate the number of peak value in this operation result.
3. the adjacent symbol that the method for claim 1, wherein produces the symbol of this peaked index be produce this peaked index symbol reach the symbol of each one second predetermined quantity backward forward.
4. method as claimed in claim 3, wherein, this second predetermined quantity is not less than 2.
5. the method for claim 1, wherein, the energy that calculates this predetermined length interval is the squared again value after the result with this computing cross-correlation gained takes absolute value, and adjusts the index of computing cross-correlation in regular turn, is the energy in this predetermined length interval behind one the 3rd predetermined quantity of adding up altogether.
6. it is this symbol period or this bit period time after divided by one the 3rd predetermined integers the method for claim 1, wherein according to the time that symbol period or bit period produced.
7. method as claimed in claim 6, wherein, the 3rd predetermined integers is 4.
8. the method for claim 1, wherein this first predetermined value is to be not less than 4 and be not more than 8 integer.
9. the method for a predicted channel impulse response in wireless communication system, it comprises:
(a) the wireless simulation conversion of signals that is received is become the fundamental frequency digital signal after, this fundamental frequency digital signal is taken a sample, will organize at least partly sampling of gained more again and carry out computing cross-correlation with one group of training string symbol of being scheduled to according to the time of symbol period or bit period generation; And
(b) if having a plurality of peak values in this operation result, then calculate square maximum of absolute value in this operation result and the ratio of second largest value; And
(c) if this ratio is not more than this first predetermined value, then utilize this computing cross-correlation result to calculate the energy in a predetermined length interval, so that the energy in this predetermined length interval is that the cross correlation value of the time step index of maximum initial index and follow-up time step index thereof is as channel impulse response.
10. method as claimed in claim 9, it comprises in addition:
(d) calculate the number of peak value in this operation result.
11. method as claimed in claim 9, wherein, make that the energy in this predetermined length interval is to make the symbol that doubles this second predetermined quantity after the symbol of energy for maximum initial index in this predetermined length interval for the adjacent symbol of the symbol of maximum initial index.
12. method as claimed in claim 11, wherein, this second predetermined quantity is not less than 2.
13. method as claimed in claim 9, wherein, the energy that calculates this predetermined length interval is a squared again value after the result with this computing cross-correlation gained takes absolute value, and adjust the index of computing cross-correlation in regular turn, be the energy in this predetermined length interval behind one the 3rd predetermined quantity of adding up altogether.
14. method as claimed in claim 9, wherein, according to the time that symbol period or bit period produced be this symbol period or this bit period time after divided by one the 3rd predetermined integers.
15. method as claimed in claim 14, wherein, the 3rd predetermined integers is 4.
16. method as claimed in claim 9, wherein, this first predetermined value is to be not less than 4 and be not more than 8 integer.
17. the method for a predicted channel impulse response in wireless communication system, it comprises:
(a) the wireless simulation conversion of signals that is received is become the fundamental frequency digital signal after, this fundamental frequency digital signal is taken a sample, will organize at least partly sampling of gained more again and carry out computing cross-correlation with one group of training string symbol of being scheduled to according to the time of symbol period or bit period generation;
(b) calculate the number of peak value in this operation result;
(c), then get the cross correlation value of peaked time step index and adjacent time step index thereof as channel impulse response with this computing cross-correlation if only have a peak value in this operation result.
18. method as claimed in claim 17, wherein, the adjacent symbol that produces the symbol of this peaked index be produce this peaked index symbol reach the symbol of each one second predetermined quantity backward forward.
19. method as claimed in claim 18, wherein, this second predetermined quantity is not less than 2.
20. method as claimed in claim 17, wherein, the energy that calculates this predetermined length interval is a squared again value after the result with this computing cross-correlation gained takes absolute value, and adjust the index of computing cross-correlation in regular turn, be the energy in this predetermined length interval behind one the 3rd predetermined quantity of adding up altogether.
21. method as claimed in claim 17, wherein, according to the time that symbol period or bit period produced be this symbol period or this bit period time after divided by one the 3rd predetermined integers.
22. method as claimed in claim 21, wherein, the 3rd predetermined integers is 4.
23. the receiver at wireless communication system, it comprises:
One internal memory is used for storing one group of predetermined training string symbol;
One cross-correlator is electrically connected to this internal memory, is used for sampling and this group training string symbol of received symbol are carried out a default computing cross-correlation;
One peak counter is used for calculating the number of peak value in this computing cross-correlation;
One peak value ratio comparator is electrically connected to this peak counter, when being used in this computing cross-correlation, having a plurality of peak value, and the relatively ratio of the maximum of this computing cross-correlation gained and second largest value and one first predetermined value;
One calculates the value module on correlation peak both sides, be electrically connected to this peak counter and this peak value ratio comparator, the ratio that is used for only having the maximum that has a plurality of peak values and this computing cross-correlation gained in a peak value or this computing cross-correlation and second largest value in this computing cross-correlation is during greater than this first predetermined value, the symbol and the adjacent symbol thereof of the peaked index that this cross-correlator is exported are as channel impulse response and export it; And
The N of one calculating energy maximum correlation module, be electrically connected to this peak value ratio comparator, when the ratio that is used for having the maximum of a plurality of peak values and this computing cross-correlation gained and second largest value in this computing cross-correlation is not more than this first predetermined value, to calculate the energy in a predetermined length interval by the output of this computing cross-correlation device, so that the energy in this predetermined length interval is not less than the symbol of the cross correlation value of 2 time step index for the symbol of maximum initial index and neighbor distance thereof, as channel impulse response and export it.
24. receiver as claimed in claim 23, wherein, the adjacent symbol of the symbol of the peaked index that this cross-correlator is exported is to make this cross-correlator export the symbol that reaches backward each one second predetermined quantity forward of the symbol of peaked index.
25. receiver as claimed in claim 24, wherein, make that the energy in this predetermined length interval is to make the symbol that doubles this second predetermined quantity after the symbol of energy for maximum initial index in this predetermined length interval for the adjacent symbol of the symbol of maximum initial index.
26. receiver as claimed in claim 23, wherein, squared again value after the N of this calculating energy maximum correlation module can take absolute value the output of this cross-correlator, and adjust the index of symbol in regular turn, one the 3rd predetermined quantity and energy that must this predetermined length interval altogether add up.
27. receiver as claimed in claim 23, wherein this first predetermined value is to be not less than 4 and be not more than 8 integer.
28. receiver as claimed in claim 23, wherein, this second predetermined quantity is not less than 2.
29. receiver as claimed in claim 23, wherein, this wireless communication system is a global system for mobile communications.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100857745A CN100539557C (en) | 2004-10-18 | 2004-10-18 | Apparatus and method for predicting channel impulse response in global system for mobile communication |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100857745A CN100539557C (en) | 2004-10-18 | 2004-10-18 | Apparatus and method for predicting channel impulse response in global system for mobile communication |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1602004A CN1602004A (en) | 2005-03-30 |
| CN100539557C true CN100539557C (en) | 2009-09-09 |
Family
ID=34667067
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004100857745A Expired - Lifetime CN100539557C (en) | 2004-10-18 | 2004-10-18 | Apparatus and method for predicting channel impulse response in global system for mobile communication |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100539557C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5151872B2 (en) * | 2007-12-27 | 2013-02-27 | セイコーエプソン株式会社 | Correlation calculation processing execution method, control circuit, signal processing circuit, and positioning device |
| WO2012106866A1 (en) * | 2011-07-05 | 2012-08-16 | 华为技术有限公司 | Signal demodulation method and receiving device |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1116381A (en) * | 1994-02-16 | 1996-02-07 | 东芝株式会社 | Sampling phase synchronizing apparatus and bidirectional maximum likelihood sequence estimation scheme therefor |
| EP0963642A1 (en) * | 1997-02-25 | 1999-12-15 | Nokia Telecommunications Oy | Channel impulse response estimation using singular value decomposition |
| CN1303192A (en) * | 1999-12-09 | 2001-07-11 | 阿尔卡塔尔公司 | Method of channel estimate in telecommunication system |
| US6400779B1 (en) * | 1997-03-12 | 2002-06-04 | Nokia Telecommunications Oy | Estimating CIR using correlation with line removal |
-
2004
- 2004-10-18 CN CNB2004100857745A patent/CN100539557C/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1116381A (en) * | 1994-02-16 | 1996-02-07 | 东芝株式会社 | Sampling phase synchronizing apparatus and bidirectional maximum likelihood sequence estimation scheme therefor |
| EP0963642A1 (en) * | 1997-02-25 | 1999-12-15 | Nokia Telecommunications Oy | Channel impulse response estimation using singular value decomposition |
| US6400779B1 (en) * | 1997-03-12 | 2002-06-04 | Nokia Telecommunications Oy | Estimating CIR using correlation with line removal |
| CN1303192A (en) * | 1999-12-09 | 2001-07-11 | 阿尔卡塔尔公司 | Method of channel estimate in telecommunication system |
Non-Patent Citations (1)
| Title |
|---|
| AU688228B B1 1998.03.05 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1602004A (en) | 2005-03-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1689292B (en) | Communication receiver with virtual parallel equalizers | |
| TW386325B (en) | Self-synchronizing equalization techniques and systems | |
| CN101379722B (en) | Equalization device and equalization method | |
| CN1433619A (en) | Equalization with DC-offset compensation | |
| CN111147407B (en) | TMSBL underwater acoustic OFDM time-varying channel estimation method based on channel prediction | |
| JPH04502695A (en) | A method of applying the Viterbi algorithm to a channel with varying transmission characteristics and an apparatus for carrying out the method | |
| CN101222458A (en) | Low-Order Recursive Minimum Mean Square Error Estimation for MIMO-OFDM Channels | |
| CN103428153B (en) | GMSK signal acceptance method in satellite mobile communication | |
| US11843429B2 (en) | Wireless communication system, wireless communication method, transmitting station device and receiving station device | |
| CN102227098B (en) | A frequency-domain bearing point selection method for multi-mode MIMO-SCFDE adaptive transmission system | |
| Wang et al. | Online LSTM-based channel estimation for HF MIMO SC-FDE system | |
| CN117792839B (en) | Approximate calculation method of Fresnel domain channel and OCDM signal demodulation method | |
| CN105162527A (en) | Underwater communication hybrid carrier method based on weighted fractional order Fourier transform | |
| Liu et al. | UACC-GAN: A Stochastic Channel Simulator for Underwater Acoustic Communication | |
| Tugnait et al. | Doubly-selective channel estimation using data-dependent superimposed training and exponential basis models | |
| CN100539557C (en) | Apparatus and method for predicting channel impulse response in global system for mobile communication | |
| Moya et al. | Broadband PLC‐channel equalisation in the frequency domain based on complementary sequences | |
| CN102045290B (en) | Gray modeling-based OFDM narrow-band slow-fading slowly time-varying channel estimation method | |
| CN103051573A (en) | Interference signal elimination module and its realization method in GSM system | |
| JPH05152894A (en) | Adaptive equalizer | |
| US20020015459A1 (en) | Method for modifying the channel impulse response in TDMA systems | |
| US20060062333A1 (en) | Method and apparatus for channel impulse response estimation in gsm systems | |
| US20060062336A1 (en) | Method of channel estimation | |
| CN100521524C (en) | Decision feed forward equalizer system and method | |
| Reangsuntea et al. | Iterative based time domain equalization method for OFDM signal under high mobile environments |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20090909 |
|
| CX01 | Expiry of patent term |