CN102143101A - Mirror-extended frequency domain windowing orthogonal frequency division multiple access channel estimation method - Google Patents

Mirror-extended frequency domain windowing orthogonal frequency division multiple access channel estimation method Download PDF

Info

Publication number
CN102143101A
CN102143101A CN2011100978792A CN201110097879A CN102143101A CN 102143101 A CN102143101 A CN 102143101A CN 2011100978792 A CN2011100978792 A CN 2011100978792A CN 201110097879 A CN201110097879 A CN 201110097879A CN 102143101 A CN102143101 A CN 102143101A
Authority
CN
China
Prior art keywords
frequency domain
length
channel
mirror image
reference signal
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.)
Pending
Application number
CN2011100978792A
Other languages
Chinese (zh)
Inventor
杨志鸿
张家军
吴镇扬
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Southeast University
Original Assignee
Southeast University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Southeast University filed Critical Southeast University
Priority to CN2011100978792A priority Critical patent/CN102143101A/en
Publication of CN102143101A publication Critical patent/CN102143101A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

The invention discloses a mirror-extended frequency domain windowing orthogonal frequency division multiple access channel estimation method, which is characterized by comprising the following steps of: 1, mirror extension, namely, performing mirror extension by L points on a received orthogonal frequency division multiple access frequency domain reference signal with the length of M points, wherein M is an orthogonal frequency division multiple access transmission bandwidth as well as the length of the reference signal in a frequency domain, and L is an extended length specifically determined by the transmission bandwidth; and 2, frequency domain windowing, namely, multiplying an obtained mirror-extended channel frequency domain response by using a window, wherein the window is an L-point ring shifts left window with the length of M+L points and adjustable parameters, the parameters are related to a signal to noise ratio, M is the orthogonal frequency division multiple access transmission bandwidth as well as the length of the reference signal in the frequency domain, and L is the extended length specifically determined by the transmission bandwidth. By the method, estimation performance can be improved, and the interference of code division multiplexing can be resisted under the condition of multiplexing the reference signals of a plurality of transmitters by different ring shifts.

Description

The frequency domain windowing OFDM channel estimation methods of mirror image expansion
Technical field
The present invention is a kind of MIMO(Multiple of being applied to Input and Multiple Output, multiple-input and multiple-output)-OFDMA(Orthogonal Frequency Division Multiple Access, OFDM) channel estimating of system belongs to the communication transmission technology field.
Background technology
Noise is also introduced in the distortion of the channel that information can be subjected in transmission course, especially in radio communication, and the radio channel state very severe, channel is a multipath, in time, become.In theory, as long as how accurately estimate channel acts on transmission signals, just can recover information transmitted.In practical communication system, often adopt the pilot tone assisted channel estimation, the known signal (claiming reference signal again) of transmitter transmission just, receiver extracts channel information from the reference signal that receives.
As a multicarrier system, OFDMA (Orthogonal Frequency Division Multiple Access, OFDM) is OFDM(Orthogonal Frequency Division Multiple, OFDM) evolution of technology, be after utilizing OFDM that channel carry out subcarrierization, on the parton carrier wave, load the transmission technology of transmission data.Because the good character of OFDMA system, can be with transmission signals and channel impulse response multiplying each other after the linear convolution on the time domain is equivalent to both to transform to frequency domain fully.Receiver obtains the reference signal of the reception on the frequency domain after the OFDM demodulation, then it just can be obtained channel frequency domain response divided by the reference signal that sends.
The channel frequency domain response that obtains above contains noise and interference, and actual communication systems need guarantee reliable channel estimating under the low signal-to-noise ratio condition.The energy major part of considering channel impulse response concentrates on the interior time domain sampling point of time delay expansion, and noise profile (it is generally acknowledged that noise is a white noise) on all time domain sampling points, the channel estimating of OFDMA system often adopts the discrete Fourier transform (DFT) based on DFT() transform domain suppress the algorithm of noise, can reach good channel estimating performance and lower complexity.Its basic scheme is that the channel frequency domain response that contains noise is done the contrary discrete Fourier transform (DFT) of IDFT() transform to time domain after, on time domain,,, suppress noise such as adding the methods such as window of dead length for the expansion of channel maximum delay by someway.
Because the transmission bandwidth of OFDMA is little with respect to system bandwidth, receiving terminal can only obtain the fraction channel frequency domain response.After channel frequency domain response is IDFT and transforms to time domain, the channel impulse response energy can leak on all sampling points, though so next time-domain windowed has kept most energy of channel impulse response, removed noise, but also removed the leakage energy of useful channel impulse response simultaneously, cause channel estimation errors on frequency domain, to be the Gibbs(gibbs) phenomenon, promptly the error on the central authorities of the channel frequency domain response estimation error ratio on the edge subcarrier subcarrier is much bigger.Even this also causes under the high s/n ratio condition, suppress the noise algorithm based on the transform domain of DFT and still have big estimated bias, also can be described as the flat phenomenon of error.
In addition, multi-antenna technology in the Modern Communication System, as space division multiple access, multipoint cooperative etc., receiver need be distinguished different transmitting terminals by the reference signal of code division multiplexing.In real system, because the concentration of energy of channel impulse response generally reaches multiplexing by different cyclic shifts in the time delay expansion.Yet, because power difference to some extent when the reference signal of different transmitting terminals receives in the real system, the energy leakage of the channel impulse response of the transmitting terminal that received power is bigger will interfere with the less transmitting terminal of received power like this, is called code division multiplexing among the present invention and disturbs.Especially under the less situation of OFDMA transmission bandwidth, the energy leakage situation of channel impulse response is more serious, thereby brings serious code division multiplexing to disturb.
Summary of the invention
Technical problem:The objective of the invention is to propose a kind of frequency domain windowing OFDM channel estimation methods of mirror image expansion, can improve the evaluated error performance, and can the reference signal of a plurality of transmitting terminals by different cyclic shift multiplexed situation under the interference of antagonism code division multiplexing.
Technical scheme:For solving the problems of the technologies described above, the present invention proposes a kind of frequency domain windowing OFDM channel estimation methods of mirror image expansion, and this method comprises the steps:
The first step, mirror image expansion: be to the length that receives
Figure 958646DEST_PATH_IMAGE001
The OFDM frequency domain reference signal of point is carried out
Figure 353855DEST_PATH_IMAGE002
The mirror image expansion of point;
Figure 466430DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 554472DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size;
Second step, frequency domain windowing: the channel frequency domain response after the mirror image expansion that obtains is multiplied by window
Figure 883822DEST_PATH_IMAGE003
, window
Figure 817143DEST_PATH_IMAGE003
Be that a length is The adjustable window of parameter of point
Figure 807282DEST_PATH_IMAGE005
Figure 358349DEST_PATH_IMAGE002
The left cyclic shift of point, wherein
Figure 921792DEST_PATH_IMAGE005
Parameter relevant with signal to noise ratio;
Figure 445177DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 671759DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size;
In the 3rd step, implement by the channel frequency domain response after mirror image expansion and the frequency domain windowing above-mentioned
Figure 913384DEST_PATH_IMAGE004
The contrary discrete Fourier transform (DFT) of point transforms to time domain;
Figure 516404DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 894296DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size;
In the 4th step, the time-domain signal that obtains is come the channel impulse response energy and the noise separation of a plurality of transmitting terminals by windowing;
The 5th step, with the channel impulse response energy trailing zero of each transmitting terminal extremely Point is implemented respectively
Figure 20701DEST_PATH_IMAGE004
The point discrete Fourier conversion transforms to frequency domain;
Figure 928876DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain, Be extension length, concrete value depends on the transmission bandwidth size;
The 6th step is before the channel frequency domain response of each transmitting terminal
Figure 995238DEST_PATH_IMAGE001
Individual divided by window Before
Figure 156278DEST_PATH_IMAGE001
Individual, obtain channel estimation results;
Figure 571079DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain.
Preferably, in the first step, mirror image expansion method be:
Figure 248048DEST_PATH_IMAGE006
Wherein,
Figure 252694DEST_PATH_IMAGE007
Be the channel frequency domain response that receives, length is
Figure 938890DEST_PATH_IMAGE001
, Be the frequency domain response after the mirror image expansion, length is
Figure 383964DEST_PATH_IMAGE009
,
Figure 309195DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 159601DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size.
Preferably, in second step, the method for frequency domain windowing is:
Wherein Be the frequency domain response after the mirror image expansion, Be frequency domain sampling point sequence number,
Figure 132925DEST_PATH_IMAGE003
Be defined as:
Figure 314508DEST_PATH_IMAGE013
，
Figure 330612DEST_PATH_IMAGE005
Be Caesar's window.
Preferably, in the 3rd step, concrete implementation method is: to the channel frequency domain response of mirror image expansion and frequency domain windowing
Figure 292752DEST_PATH_IMAGE014
Implement
Figure 858862DEST_PATH_IMAGE009
The contrary discrete Fourier transform (DFT) of point transforms to time-domain signal
Figure 957268DEST_PATH_IMAGE015
Figure 583422DEST_PATH_IMAGE016
Wherein,
Figure 767278DEST_PATH_IMAGE012
Be frequency domain sampling point sequence number,
Figure 137080DEST_PATH_IMAGE017
Be time domain sampling point sequence number;
Figure 857037DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 654091DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size.
Preferably, in the 5th step, concrete implementation method: to the channel impulse response of each transmitting terminal
Figure 325244DEST_PATH_IMAGE018
Do respectively
Figure 233157DEST_PATH_IMAGE009
Discrete Fourier transform (DFT) obtains the domain channel response of a plurality of transmitting terminals
Figure 306155DEST_PATH_IMAGE019
, wherein iIn order to distinguish different user;
Figure 274111DEST_PATH_IMAGE020
Be frequency domain sampling point sequence number, Be time domain sampling point sequence number;
Figure 665862DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 867036DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size.
Preferably, in the 6th step, concrete implementation method: to each user's
Figure 184885DEST_PATH_IMAGE019
Before
Figure 762496DEST_PATH_IMAGE001
Individual sampling point is divided by window function
Figure 810087DEST_PATH_IMAGE021
, promptly
Figure 119846DEST_PATH_IMAGE022
Figure 488772DEST_PATH_IMAGE012
Be frequency domain sampling point sequence number, iIn order to distinguish different user; Obtain a plurality of users' channel frequency domain response
Figure 542179DEST_PATH_IMAGE023
Beneficial effect:The present invention had carried out windowing and mirror image expansion to domain channel response before channel estimating transforms to time domain, mirror image extended method wherein, the discontinuous position of the frequency response of edge subcarrier has been extended between the pseudo channel frequency domain response, can alleviate the Gibbs(gibbs of evaluated error) phenomenon, thereby improve the flat effect of error, and windowing can fundamentally improve the Energy Leaking of multipath, can further promote estimated performance.At a plurality of transmitting terminals
Figure 444276DEST_PATH_IMAGE024
Reference signal by under the multiplexing scene of different cyclic shifts, windowing can effectively suppress code division multiplexing to be disturbed, and improves estimated performance.
Description of drawings
Fig. 1 is the flow chart of the frequency domain windowing channel estimation method of mirror image expansion.
Embodiment
Channel estimation methods of the present invention is: supposing the system is OFDMA(Orthogonal Frequency Division Multiple Access, OFDM) system, have
Figure 924936DEST_PATH_IMAGE025
The reference signal with different cyclic shifts of individual transmitter sends on identical time-frequency domain resources piece simultaneously.
Receiver receives the OFDMA time-domain signal, by OFDM(Orthogonal Frequency Division Multiple, OFDM) separate and be in harmonious proportion step such as resource inverse mapping, obtain the frequency domain reference signal, as the input of channel estimation module.
For convenience of description, at first define following variable: the channel frequency domain response that receiver obtains
Figure 545273DEST_PATH_IMAGE026
Be defined as:
Figure 136791DEST_PATH_IMAGE027
[1]
Wherein
Figure 158974DEST_PATH_IMAGE028
Being through OFDM(Orthogonal Frequency Division Multiple, OFDM) the frequency domain reference signal that obtains of demodulation and inverse mapping (comprises PIndividual transmitting terminal
Figure 371387DEST_PATH_IMAGE024
The frequency domain reference signal), MBeing the OFDMA transfer bandwidth, also is the length of reference signal on frequency domain.
Figure 151124DEST_PATH_IMAGE029
It is the reference signal on the local frequency domain.
Figure 608650DEST_PATH_IMAGE012
Represent frequency domain sampling point sequence number.
In order to guarantee the continuity of edge channel frequency domain response expansion, introduce virtual domain channel response, the present invention is defined as a kind of mirror image expansion with it, and the mirror image of its both sides frequency domain response is added at the end that is about to original channel frequency domain response
Figure 423023DEST_PATH_IMAGE030
[2]
Wherein LGeneral value is 1 to arrive K, concrete value depends on the transmission bandwidth size.
The domain channel response that obtains after the definition windowing:
Figure 307802DEST_PATH_IMAGE010
[3]
Wherein,
Figure 574835DEST_PATH_IMAGE003
Be defined as the adjustable window function of a kind of parameter
Figure 836052DEST_PATH_IMAGE005
(as Kaiser(Kai Se) window) LThe left cyclic shift version of sampling point:
Figure 68713DEST_PATH_IMAGE013
[4]
Wherein
Figure 62077DEST_PATH_IMAGE005
Can adopt fixing window, also can adjust according to current signal to noise ratio, when signal to noise ratio big,
Figure 878723DEST_PATH_IMAGE005
Can select the window of bigger curvature, and it is little to work as signal to noise ratio,
Figure 881314DEST_PATH_IMAGE005
Can select the window of less curvature.
Right
Figure 467016DEST_PATH_IMAGE031
Carry out
Figure 693598DEST_PATH_IMAGE032
Point IDFT conversion obtains time-domain signal
Figure 935224DEST_PATH_IMAGE015
:
[5]
According to the reference signal cyclic shift value of different transmitting terminals, to time-domain signal The rectangular window that adds diverse location intercepts out the sampling point of each user's the main energy of channel impulse response respectively.Here suppose MBe the maximum delay extension length, be 0 reference signal if user A adopts cyclic shift value, and the position of window is positioned at the beginning of signal so MOn the individual sampling point.If it is 1/2 reference signal that user B adopts cyclic shift value, so the position of window be positioned at signal in the middle of beginning MOn the individual sampling point, and the like.With the trailing zero of the main energy sampling point of each user's channel impulse response extremely Point obtains PThe channel impulse response of individual transmitting terminal
Channel impulse response to each transmitting terminal
Figure 953645DEST_PATH_IMAGE018
Do respectively
Figure 248360DEST_PATH_IMAGE032
Point DFT obtains a plurality of transmitting terminals
Figure 20007DEST_PATH_IMAGE024
Domain channel response
Figure 534427DEST_PATH_IMAGE019
:
Figure 416933DEST_PATH_IMAGE020
[6]
Owing to before multi-user's frequency domain response has been taked the frequency domain windowing, has needed frequency domain response here to each user
Figure 831733DEST_PATH_IMAGE019
Pass through divided by window function respectively
Figure 836599DEST_PATH_IMAGE033
Remove and add window effect, in addition, each user gone frequency domain response after the windowing will cast out end length to be LMirror image expansion.Can will go windowing and remove two steps of mirror image expansion and merge into a step, also promptly:
Figure 274533DEST_PATH_IMAGE034
[7]
Like this, obtain PIndividual user's channel frequency domain response
Figure 23046DEST_PATH_IMAGE023
, as the output of channel estimation module.
Based on above discussion, we propose following OFDMA channel estimation methods.
The first step to the length that receives is MThe OFDMA frequency domain reference signal of point is carried out LThe mirror image expansion of point.
In second step, the channel frequency domain response after the expansion that obtains is multiplied by a window that parameter is adjustable
Figure 230037DEST_PATH_IMAGE003
,
Figure 904338DEST_PATH_IMAGE003
Parameter can be relevant with signal to noise ratio.
In the 3rd step, the channel frequency domain response after frequency domain windowing and the mirror image expansion is implemented
Figure 891886DEST_PATH_IMAGE032
Point IDFT transforms to time domain.
In the 4th step, the time-domain signal that obtains is come the channel impulse response energy and the noise separation of a plurality of transmitting terminals by windowing.
The 5th step, with the zero padding of the main energy sampling point of the channel impulse response of each transmitting terminal extremely
Figure 116194DEST_PATH_IMAGE032
Point is implemented respectively
Figure 505587DEST_PATH_IMAGE032
Point DFT is transformed to domain channel response.
In the 6th step, preceding M of the domain channel response of each transmitting terminal put divided by window function
Figure 524358DEST_PATH_IMAGE005
, obtain channel estimation results.
The present invention proposes a kind of MIMO-OFDMA system channel estimation approach.
Adopting the virtual MIMO mode with two users in the LTE system also is under the space division multiple access situation, and bandwidth is that the uplink demodulation reference signal of 24 subcarriers is that example provides a kind of embodiment by the multiplexing BTS channel estimation scheme of different cyclic shifts:
The first step is carried out the OFDM demodulation with the OFDMA signal of a symbol lengths receiving, through the resource inverse mapping, obtains comprising the frequency-region signal of two users' demodulated reference signal.
In second step, it is 6 mirror image expansion that the frequency-region signal that previous step is obtained carries out length according to formula [2].
In the 3rd step, the frequency-region signal point after the expansion be multiply by 30 length Kaiser6 the left cyclic shift version of (Caesar) window.
In the 4th step, 30 the frequency-region signal that previous step expansion is obtained carries out 30 IDFT and transforms to time domain.
In the 5th step, 30 the time-domain signal that previous step is obtained carries out the windowing zero padding according to user's cyclic shift position, obtains two users' channel impulse response.
The 6th step, the channel impulse response of 30 sampling points of two users is carried out 30 DFT conversion respectively, obtain two users' frequency domain response.
In the 7th step, preceding 24 sampling points of two users' that the 6th step was obtained frequency domain response are divided by 30 length Kaiser24 points of the central authorities of (Caesar) window, 24 sampling points of two users are exactly the channel frequency domain response estimation value that the present invention obtains.
The present invention proposes the channel estimation method of a kind of MIMO-OFDMA of being suitable for system, can effectively promote channel estimating performance, and the antagonism code division multiplexing disturbs.
The first step is that the OFDMA frequency domain reference signal that M is ordered is carried out the mirror image expansion that L is ordered to the length that receives.
In second step, the channel frequency domain response after the expansion that obtains is multiplied by a window that parameter is adjustable
Figure 999202DEST_PATH_IMAGE003
,
Figure 27201DEST_PATH_IMAGE003
Parameter can be relevant with signal to noise ratio.
In the 3rd step, the channel frequency domain response after frequency domain windowing and the mirror image expansion is implemented
Figure 772565DEST_PATH_IMAGE032
Point DFT transforms to time domain.
In the 4th step, the time-domain signal that obtains is come the channel impulse response energy and the noise separation of a plurality of transmitting terminals by windowing.
The 5th step, with the channel impulse response energy trailing zero of each transmitting terminal extremely
Figure 227817DEST_PATH_IMAGE032
Point is implemented respectively Point IDFT transforms to frequency domain.
In the 6th step, preceding M of the channel frequency domain response of each transmitting terminal put divided by window
Figure 490489DEST_PATH_IMAGE003
Before
Figure 854474DEST_PATH_IMAGE001
Individual, obtain channel estimation results.

Claims (6)

1. the frequency domain windowing OFDM channel estimation methods of mirror image expansion, it is characterized in that: this method comprises the steps:
The first step, mirror image expansion: be to the length that receives
Figure 696373DEST_PATH_IMAGE001
The OFDM frequency domain reference signal of point is carried out
Figure 305209DEST_PATH_IMAGE002
The mirror image expansion of point;
Figure 275439DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 348437DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size;
Second step, frequency domain windowing: the channel frequency domain response after the mirror image expansion that obtains is multiplied by window
Figure 316393DEST_PATH_IMAGE003
, window Be that a length is
Figure 186446DEST_PATH_IMAGE004
The adjustable window of parameter of point
Figure 880995DEST_PATH_IMAGE005
Figure 19853DEST_PATH_IMAGE002
The left cyclic shift of point, wherein
Figure 400018DEST_PATH_IMAGE005
Parameter relevant with signal to noise ratio;
Figure 915313DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 962904DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size;
In the 3rd step, implement by the channel frequency domain response after mirror image expansion and the frequency domain windowing above-mentioned
Figure 272662DEST_PATH_IMAGE004
The contrary discrete Fourier transform (DFT) of point transforms to time domain;
Figure 140124DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 771961DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size;
In the 4th step, the time-domain signal that obtains is come the channel impulse response energy and the noise separation of a plurality of transmitting terminals by windowing;
The 5th step, with the channel impulse response energy trailing zero of each transmitting terminal extremely
Figure 611741DEST_PATH_IMAGE004
Point is implemented respectively
Figure 154718DEST_PATH_IMAGE004
The point discrete Fourier conversion transforms to frequency domain;
Figure 712738DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 366573DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size;
The 6th step is before the channel frequency domain response of each transmitting terminal
Figure 326439DEST_PATH_IMAGE001
Individual divided by window
Figure 40317DEST_PATH_IMAGE003
Before Individual, obtain channel estimation results;
Figure 779045DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain.
2. the frequency domain windowing OFDM channel estimation methods of mirror image according to claim 1 expansion is characterized in that: in the first step, the mirror image expansion method be:
Figure 593418DEST_PATH_IMAGE006
Wherein,
Figure 478197DEST_PATH_IMAGE007
Be the channel frequency domain response that receives, length is ,
Figure 6447DEST_PATH_IMAGE008
Be the frequency domain response after the mirror image expansion, length is
Figure 737643DEST_PATH_IMAGE009
, Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 46188DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size.
3. the frequency domain windowing OFDM channel estimation methods of mirror image expansion according to claim 1 is characterized in that: in second step, the method for frequency domain windowing is:
Figure 48779DEST_PATH_IMAGE010
Wherein
Figure 634481DEST_PATH_IMAGE011
Be the frequency domain response after the mirror image expansion, Be frequency domain sampling point sequence number,
Figure 102689DEST_PATH_IMAGE003
Be defined as:
Figure 643392DEST_PATH_IMAGE013
,
Figure 83600DEST_PATH_IMAGE005
Be Caesar's window.
4. the frequency domain windowing OFDM channel estimation methods of mirror image expansion according to claim 1 is characterized in that: in the 3rd step, concrete implementation method is: to the channel frequency domain response of mirror image expansion and frequency domain windowing
Figure 248128DEST_PATH_IMAGE014
Implement
Figure 711470DEST_PATH_IMAGE009
The contrary discrete Fourier transform (DFT) of point transforms to time-domain signal
Figure 350579DEST_PATH_IMAGE016
Wherein,
Figure 184543DEST_PATH_IMAGE012
Be frequency domain sampling point sequence number,
Figure 197498DEST_PATH_IMAGE017
Be time domain sampling point sequence number;
Figure 80003DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 999199DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size.
5. the frequency domain windowing OFDM channel estimation methods of mirror image expansion according to claim 1 is characterized in that: in the 5th step, and concrete implementation method: to the channel impulse response of each transmitting terminal
Figure 941747DEST_PATH_IMAGE018
Do respectively
Figure 441998DEST_PATH_IMAGE009
Discrete Fourier transform (DFT) obtains the domain channel response of a plurality of transmitting terminals
Figure 128195DEST_PATH_IMAGE019
, wherein iIn order to distinguish different user;
Figure 397502DEST_PATH_IMAGE020
Figure 510951DEST_PATH_IMAGE012
Be frequency domain sampling point sequence number,
Figure 498499DEST_PATH_IMAGE017
Be time domain sampling point sequence number;
Figure 722807DEST_PATH_IMAGE001
Being the OFDM transfer bandwidth, also is the length of reference signal on frequency domain,
Figure 613665DEST_PATH_IMAGE002
Be extension length, concrete value depends on the transmission bandwidth size.
6. the frequency domain windowing OFDM channel estimation methods of mirror image expansion according to claim 1 is characterized in that: in the 6th step, and concrete implementation method: to each user's
Figure 694753DEST_PATH_IMAGE019
Before
Figure 107280DEST_PATH_IMAGE001
Individual sampling point is divided by window function
Figure 197596DEST_PATH_IMAGE021
, promptly
Figure 379178DEST_PATH_IMAGE022
Figure 896747DEST_PATH_IMAGE012
Be frequency domain sampling point sequence number, iIn order to distinguish different user; Obtain a plurality of users' channel frequency domain response
Figure 91843DEST_PATH_IMAGE023
CN2011100978792A 2011-04-19 2011-04-19 Mirror-extended frequency domain windowing orthogonal frequency division multiple access channel estimation method Pending CN102143101A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2011100978792A CN102143101A (en) 2011-04-19 2011-04-19 Mirror-extended frequency domain windowing orthogonal frequency division multiple access channel estimation method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2011100978792A CN102143101A (en) 2011-04-19 2011-04-19 Mirror-extended frequency domain windowing orthogonal frequency division multiple access channel estimation method

Publications (1)

Publication Number Publication Date
CN102143101A true CN102143101A (en) 2011-08-03

Family

ID=44410336

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2011100978792A Pending CN102143101A (en) 2011-04-19 2011-04-19 Mirror-extended frequency domain windowing orthogonal frequency division multiple access channel estimation method

Country Status (1)

Country Link
CN (1) CN102143101A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102611656A (en) * 2012-03-21 2012-07-25 武汉邮电科学研究院 Enhanced channel estimation method and enhanced channel estimation device suitable for uplink of LTE (long term evolution) system
CN104836766A (en) * 2015-03-31 2015-08-12 杭州祥声通讯股份有限公司 High-speed train base station signal receiver
CN105530208A (en) * 2014-09-28 2016-04-27 联想(北京)有限公司 Information processing method and electronic device
US9654306B1 (en) 2015-11-17 2017-05-16 Futurewei Technologies, Inc. System and method for multi-source channel estimation
WO2017084583A1 (en) * 2015-11-17 2017-05-26 Huawei Technologies Co., Ltd. System and method for multi-source channel estimation
CN111049766A (en) * 2019-11-26 2020-04-21 重庆邮电大学 Estimation method for PDSCH of 5G system
US10638479B2 (en) 2015-11-17 2020-04-28 Futurewei Technologies, Inc. System and method for multi-source channel estimation
CN114745236A (en) * 2022-04-07 2022-07-12 展讯通信（上海）有限公司 Data preprocessing method and device for transform domain channel estimation and communication equipment
CN114844582A (en) * 2022-04-07 2022-08-02 展讯通信（上海）有限公司 Method and device for estimating signal-to-noise ratio of transform domain and communication equipment

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090034503A1 (en) * 2007-07-31 2009-02-05 Samsung Electronics Co. Ltd. Receiver and reception method for estimating channel in an orthogonal frequency division multiple access system
CN101512946A (en) * 2006-06-01 2009-08-19 高通股份有限公司 Enhanced channel estimation for communication system receiver
CN101888359A (en) * 2009-05-13 2010-11-17 清华大学 Multi-address access system based on TDS-OFDM (Time-Domain Synchronous Orthogonal Frequency Division Multiplexing) as well as signal frame structure and receiving method thereof
CN101997807A (en) * 2009-08-31 2011-03-30 大唐移动通信设备有限公司 Channel estimation method and device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101512946A (en) * 2006-06-01 2009-08-19 高通股份有限公司 Enhanced channel estimation for communication system receiver
US20090034503A1 (en) * 2007-07-31 2009-02-05 Samsung Electronics Co. Ltd. Receiver and reception method for estimating channel in an orthogonal frequency division multiple access system
CN101888359A (en) * 2009-05-13 2010-11-17 清华大学 Multi-address access system based on TDS-OFDM (Time-Domain Synchronous Orthogonal Frequency Division Multiplexing) as well as signal frame structure and receiving method thereof
CN101997807A (en) * 2009-08-31 2011-03-30 大唐移动通信设备有限公司 Channel estimation method and device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
王建华等: "《MIMO-OFDMA***中理想信道估计》", 《深圳信息职业技术学院学报》, vol. 6, no. 2, 30 June 2008 (2008-06-30), pages 55 - 58 *

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102611656A (en) * 2012-03-21 2012-07-25 武汉邮电科学研究院 Enhanced channel estimation method and enhanced channel estimation device suitable for uplink of LTE (long term evolution) system
CN105530208A (en) * 2014-09-28 2016-04-27 联想(北京)有限公司 Information processing method and electronic device
CN105530208B (en) * 2014-09-28 2019-06-25 联想(北京)有限公司 A kind of information processing method and electronic equipment
CN104836766A (en) * 2015-03-31 2015-08-12 杭州祥声通讯股份有限公司 High-speed train base station signal receiver
CN104836766B (en) * 2015-03-31 2019-11-29 东阳市琰安建筑工程有限公司 Bullet train base station signal receiver
US9800384B2 (en) 2015-11-17 2017-10-24 Futurewei Technologies, Inc. System and method for multi-source channel estimation
WO2017084583A1 (en) * 2015-11-17 2017-05-26 Huawei Technologies Co., Ltd. System and method for multi-source channel estimation
WO2017084581A1 (en) * 2015-11-17 2017-05-26 Huawei Technologies Co., Ltd. System and method for multi-source channel estimation
US9654306B1 (en) 2015-11-17 2017-05-16 Futurewei Technologies, Inc. System and method for multi-source channel estimation
US10638479B2 (en) 2015-11-17 2020-04-28 Futurewei Technologies, Inc. System and method for multi-source channel estimation
CN111049766A (en) * 2019-11-26 2020-04-21 重庆邮电大学 Estimation method for PDSCH of 5G system
CN114745236A (en) * 2022-04-07 2022-07-12 展讯通信（上海）有限公司 Data preprocessing method and device for transform domain channel estimation and communication equipment
CN114844582A (en) * 2022-04-07 2022-08-02 展讯通信（上海）有限公司 Method and device for estimating signal-to-noise ratio of transform domain and communication equipment

Similar Documents

Publication Publication Date Title
CN102143101A (en) Mirror-extended frequency domain windowing orthogonal frequency division multiple access channel estimation method
CN102687441B (en) Channel estimation for OFDM systems
US8681912B2 (en) Method and apparatus for estimating channel using phase compensation in wireless communication system
JP4832261B2 (en) Channel estimation device
CN101577692B (en) Channel estimating method of orthogonal frequency division multiplexing system and device thereof
US8548101B2 (en) Demodulation method and demodulator for orthogonal frequency multiplexing—multiple input multiple output system
CN101127753B (en) A channel estimation method applicable to multi-carrier system
KR100896654B1 (en) Apparatus and method for estimating delay spread of multi-path fading channel in ofdm system
JPWO2006098147A1 (en) Wireless communication apparatus and channel estimation and separation method in multi-input system
EP2544391A1 (en) Channel estimation circuit, channel estimation method, and receiver
WO2012093333A1 (en) Method of channel estimation, method of selecting pilot information, user equipment, and base station
CN103036820A (en) Multi-cell channel estimation method and device based on reference signals
CN102761504B (en) Estimation method for TD-LTE digital relay downlink channel
CN102113285A (en) A simplified equalizationscheme for distributed resource allocation in multi-carrier systems
US20080240262A1 (en) Ofdm/ofdma channel estimation
CN103634259A (en) Multi-antenna single carrier wave frequency division multi-address system timing synchronous parallel interference eliminating method
CN102035787B (en) Band sequencing Turbo enhancement method for multiple-input multiple-output-orthogonal frequency division multiplexing (MIMO-OFDM) wireless communication receiver
CN101848183A (en) Channel estimation method and device in multiple input multiple output OFDM (Orthogonal Frequency Division Multiplexing) system
CN101795249B (en) Receiving apparatus with frequency domain equalizer
CN102065035B (en) Channel estimation method of multi-band orthogonal frequency-division multiplexing ultra-wideband system
Jie et al. An improved DFT-based channel estimation algorithm for MIMO-OFDM systems
KR101329335B1 (en) Apparatus and method for estimating of channel in frequency domain
JP5349206B2 (en) Intercarrier interference canceling apparatus and intercarrier interference canceling method
CN102223336B (en) Wireless communication method and equipment
KR100992369B1 (en) Apparatus for estimating channel of ofdm system

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C02 Deemed withdrawal of patent application after publication (patent law 2001)
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20110803