CN107276627A - Signal processing method and system - Google Patents

Signal processing method and system Download PDF

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Publication number
CN107276627A
CN107276627A CN201610219190.5A CN201610219190A CN107276627A CN 107276627 A CN107276627 A CN 107276627A CN 201610219190 A CN201610219190 A CN 201610219190A CN 107276627 A CN107276627 A CN 107276627A
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las
training sequence
codes
code
signal
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CN107276627B (en
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不公告发明人
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JIANGSU YITONG CONTROL SYSTEM Co.,Ltd.
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Shenzhen Super Data Link Technology Ltd
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Priority to PCT/CN2017/079580 priority patent/WO2017174003A1/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H04B1/707—Spread spectrum techniques using direct sequence modulation
    • H04B1/7073—Synchronisation aspects
    • H04B1/7087—Carrier synchronisation aspects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J13/00—Code division multiplex systems
    • H04J13/10—Code generation
    • H04J13/12—Generation of orthogonal codes

Abstract

The invention provides a kind of signal processing method, including：Pretreatment is performed to the reception signal from transmitting terminal, the reception signal is the code division overlapped signal from transmitting terminal and including training sequence and data based on midamble code, wherein training sequence frequency range is more than power spectral density of the power spectral density less than data of data bandwidth and training sequence, and execution pretreatment includes performing pretreatment to the reception signal using the training sequence based on midamble code.The present invention is higher to the synchronization accuracy of time and frequency, thus can improve the success rate and access speed of user access network, makes Consumer's Experience better.

Description

Signal processing method and system
Technical field
The present invention relates generally to wireless communication system, more particularly to a kind of signal processing method and system.
Background technology
Cordless communication network is widely deployed each to provide voice, video, grouped data, information receiving, broadcast etc. Plant communication service.These wireless networks can support the multiple access net of multiple users by sharing available Internet resources Network.The example of this kind of multi-access network includes CDMA (CDMA) network, time division multiple acess (TDMA) network, frequency division multiple access (FDMA) Network, orthogonal FDMA (OFDMA) networks and Single Carrier Frequency Division Multiple Access (SC-FDMA) network.
With global mobile communication constantly enhanced demand, the frequency resource of radio communication is more nervous.Therefore, except base Composed in TDM (time division multiplexing), FDM (frequency division multiplexing) above-mentioned conventional highfrequency outside the wireless communication system of utilization rate, it is also proposed that There is the more radical communication plan of more high usage for frequency spectrum.
System is exactly so for overlapped time division multiplexing (Overlapped Time Division Multiplexing, OvTDM) A kind of scheme for improving system spectral efficiency., not only need not be mutually isolated between symbol in OvTDM systems, and can be with There is very strong mutual overlapping.In other words, the overlapping between OvTDM systems are by being artificially induced symbol, is existed using multiple symbols Time-domain parallel transmits data sequence, and the availability of frequency spectrum greatly improved.
Overlapping frequency division multiplexing (Overlapped Frequency Division Multiplexing, OvFDM) system is Another improves the scheme of system spectral efficiency.Can have in OvFDM systems, between sub-carrier band and compare orthogonal frequency division multiplexing With stronger overlapping of OFDM.By overlapping degree higher between each sub-band in frequency domain, one is entered on the basis of ofdm system Step improves the availability of frequency spectrum.
Although above-mentioned OvTDM systems and OvFDM systems have it is corresponding receive demodulation scheme exclude signal in time domain or Overlapping the brought interference of frequency domain, but the reception greatly improved still to signal of the availability of frequency spectrum proposes higher want Ask.
Therefore, OvTDM systems and OvFDM systems need the network insertion scheme of higher performance.And existing communication system The m-sequence used can not meet demand for training sequence.
The content of the invention
The brief overview of one or more aspects given below is to provide to the basic comprehension in terms of these.This general introduction is not The extensive overview of all aspects contemplated, and it is also non-to be both not intended to identify the key or decisive key element of all aspects Attempt to define the scope in terms of any or all.Its unique purpose is to provide the one of one or more aspects in simplified form A little concepts think the sequence of more detailed description given later.
It is an object of the present invention to when using M sequence for existing communication system for training sequence, because M sequence is from phase Close and cross correlation is poor, cause system synchronization procedure success rate low, there is provided a kind of communication means for the slow defect of network insertion And system, to overcome above mentioned problem.
According to an aspect of the present invention there is provided a kind of signal processing method, including：
Pretreatment is performed to the reception signal from transmitting terminal, the reception signal is the code division overlapped signal from transmitting terminal And including training sequence and data based on midamble code, wherein training sequence frequency range is more than the work(of data bandwidth and training sequence Rate spectrum density is less than the power spectral density of data, and execution pretreatment includes：
Pretreatment is performed to the reception signal using the training sequence based on midamble code.
In one example, this is included following using the training sequence based on midamble code to reception signal execution pretreatment At least one：
Timing Synchronization is performed to the reception signal using the training sequence based on midamble code；
Carrier synchronization is performed to the reception signal using the training sequence based on midamble code；Or
Channel estimation is performed to the reception signal using the training sequence based on midamble code.
In one example, the midamble code includes m-sequence, Golomb codes, CAN codes or LAS codes.
In one example, 5 times, 10 times, 15 times or more of the training sequence frequency range more than data bandwidth.
In one example, the training sequence includes at least one LAS short code [Xlas]SN, SN is the length of the LAS short codes, should Performing pretreatment to the reception signal using the training sequence based on midamble code includes：
Timing Synchronization is performed to the reception signal using at least one LAS short code.
In one example, the training sequence includes two LAS short codes, and this uses the training sequence pair based on midamble code The reception signal, which performs pretreatment, also to be included：
Carrier synchronization is performed to the reception signal using two LAS short codes.
In one example, the training sequence includes：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN, wherein [0]SNIt is for length SN 0 sequence.
In one example, the training sequence also includes two LAS long codes [Xlas]LN, LN is the length of the LAS long codes, and this is adopted Performing pretreatment to the reception signal with the training sequence based on midamble code also includes：
Using two LAS long codes to the secondary execution carrier synchronization of the reception signal Jing Guo carrier synchronization.
In one example, this performs pretreatment to the reception signal using the training sequence based on midamble code and also included：
Channel estimation is performed to the reception signal through carrier synchronization using any one of this two long LAS codes.
In one example, this performs pretreatment to the reception signal using the training sequence based on midamble code and also included：
Channel estimation twice is performed to the reception signal through carrier synchronization using this two long LAS codes.
In one example, the training sequence includes：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN, its In [0]SNFor 0 sequence that length is SN.
According to another aspect of the present invention there is provided a kind of signal processing apparatus, including：
Pretreatment unit, for performing pretreatment to the reception signal from transmitting terminal, the reception signal is from transmission The code division overlapped signal at end and including training sequence and data based on midamble code, wherein training sequence frequency range is more than data frequency The power spectral density of wide and training sequence is less than the power spectral density of data, and the pretreatment unit uses the instruction based on midamble code The white silk sequence pair reception signal performs pretreatment.
In one example, pretreatment unit includes at least one of：
Time synchronization unit, for performing Timing Synchronization to the reception signal using the training sequence based on midamble code；
Carrier synchronization unit, for performing carrier synchronization to the reception signal using the training sequence based on midamble code； Or
Channel estimating unit, for performing channel estimation to the reception signal using the training sequence based on midamble code.
In one example, the midamble code includes m-sequence, Golomb codes, CAN codes or LAS codes.
In one example, 5 times, 10 times, 15 times or more of the training sequence frequency range more than data bandwidth.
In one example, the training sequence includes at least one LAS short code [Xlas]SN, SN is the length of the LAS short codes, should Pretreatment unit includes the time synchronization unit, and the time synchronization unit is further used for using at least one LAS short code pair The reception signal performs Timing Synchronization.
In one example, the training sequence includes two LAS short codes, and the pretreatment unit also includes the carrier synchronization list Member, the carrier synchronization unit is further used for performing carrier synchronization to the reception signal using two LAS short codes.
In one example, the training sequence includes：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN, wherein [0]SNIt is for length SN 0 sequence.
In one example, the training sequence also includes two LAS long codes [Xlas]LN, LN is the length of the LAS long codes, the load Ripple synchronization unit is further used for same using two LAS long codes execution carrier wave secondary to the reception signal Jing Guo carrier synchronization Step.
In one example, the pretreatment unit also includes the channel estimating unit, and the channel estimating unit is further used for Channel estimation is performed to the reception signal through carrier synchronization using any one of two long midamble codes.
In one example, the pretreatment unit also includes the channel estimating unit, and the channel estimating unit is further used for Channel estimation twice is performed to the reception signal through carrier synchronization using two long midamble codes.
In one example, the training sequence includes：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN, its In [0]SNFor 0 sequence that length is SN.
The present invention has following beneficial effect：The present invention is utilized by designing in systems using LAS codes as training sequence It is zero everywhere beyond preferable impulse function, origin that LAS codes auto-correlation function is in origin, and cross-correlation function is zero everywhere Characteristic, when solving practical communication system and using M sequence for training sequence, because M sequence auto-correlation and cross correlation are poor, Cause system synchronization procedure success rate relatively low, the problem of network insertion is slow.Realize when using LAS codes for training sequence, in letter In number processing procedure, including Timing Synchronization, carrier synchronization, channel estimation, it is higher to the synchronization accuracy of time and frequency, thus can The success rate and access speed of user access network are improved, makes Consumer's Experience better.
Brief description of the drawings
After the detailed description of embodiment of the disclosure is read in conjunction with the following drawings, it better understood when the present invention's Features described above and advantage.In the accompanying drawings, each component is not necessarily drawn to scale, and with similar correlation properties or feature Component may have same or like reference.
Fig. 1 shows the block diagram of the transmitting terminal modulation module of OvTDM systems；
Fig. 2 shows the block diagram of the signal pre-processing module of the receiving terminal of OvTDM systems；
Fig. 3 shows the block diagram of the receiving terminal sequence detection module of OvTDM systems；
Fig. 4 shows the modulation module block diagram of the transmitting terminal of OvFDM systems；
Fig. 5 shows the block diagram of the signal pre-processing module of the receiving terminal of OvFDM systems；
Fig. 6 shows the block diagram of the signal detection module of the receiving terminal of OvFDM systems；
Fig. 7 shows the autocorrelation performance of M sequence；
Fig. 8 shows the autocorrelation performance of LAS codes；
Fig. 9 shows the distribution map of the autocorrelation result of Timing Synchronization；
Figure 10 shows the schematic diagram for detecting the training sequence under two peak value situations；
Figure 11 shows the block diagram of the time synchronization unit of receiving terminal according to an aspect of the present invention；
Figure 12 shows the flow chart of time synchronization method according to an aspect of the present invention；
Figure 13 shows the block diagram of carrier synchronization unit according to an aspect of the present invention；
Figure 14 shows the flow chart of carrier synchronization method according to an aspect of the present invention；
Figure 15 shows the flow chart of carrier synchronization method according to an aspect of the present invention；
Figure 16 shows the arrangement schematic diagram of multipath channel；
Figure 17 shows training sequence according to an aspect of the present invention and the frequency range and power spectral density graph of a relation of data；
Figure 18 shows two carrier signals according to an aspect of the present invention while spectrum diagram when sending data；
Figure 19 is OvCDM system functional block diagrams；
Figure 20 is OvCDM encoder schematic diagram.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.Note, it is below in conjunction with accompanying drawing and specifically real It is only exemplary to apply the aspects of example description, and is understood not to carry out any limitation to protection scope of the present invention.
Except applying in OvTDM and OvFDM systems, all technologies described herein are also widely applied to actual shifting In dynamic communication system, such as TD-LTE, TD-SCDMA system is also widely applied to satellite communication, microwave horizon communication, scattering Communication, atmosphere optic communication, infrared communication with aquatic any wireless communication system such as communicate.Term " network " and " system " Often it is used interchangeably.
Mobile communication continue to develop and new business emerge in an endless stream message transmission rate is proposed it is higher and higher It is required that, and the frequency resource of mobile communication is extremely limited, and the high-speed transfer of data how is realized using limited frequency resource The major issue faced as current mobile communication technology
Above-mentioned OvTDM and OvFDM systems are exactly this can to greatly improve the solution of the availability of frequency spectrum.It is brief below That introduces OvTDM systems sends and receives process.
OvTDM systems are using multiple symbols in time-domain transmitting data in parallel sequence.Multiple symbols are formed in transmitting terminal to exist Overlapped transmission signal in time-domain, in receiving terminal according between transmission data sequence and transmission data sequence time waveform One-to-one relationship, docking collect mail number carry out time-domain in by a data sequence detection.OvTDM systems are actively heavy using these It is folded to be allowed to produce coding bound relation, so that the spectrum efficiency of system is greatly improved.
Fig. 1 shows the block diagram of the transmitting terminal modulation module of OvTDM systems.Transmitting terminal modulation module 100 may include numeral Waveform generating unit 110, shifting deposit unit 120, multiplication unit 130 and adder unit 140.
First, first modulated signal that generation sends signal is designed in a digital manner by digital waveform generating unit 110 The envelope waveform h (t) is carried out special time displacement by envelope waveform h (t), shifting deposit unit 120, forms each other moment The envelope waveform h (t-i × Δ T) of modulated signal, multiplication unit 130 is by the parallel symbol x to be sentiWith the corresponding moment Envelope waveform h (t-i × Δ T) be multiplied, obtain each moment it is modulated after signal waveform x to be sentih(t-i×ΔT).Plus Each waveform to be sent formed is overlapped by method unit 140, forms transmission signal waveform.
The receiving terminal of OvTDM systems is broadly divided into signal pre-processing module 200 and sequence detection module 300.Fig. 2 is shown The block diagram of the signal pre-processing module 200 of the receiving terminal of OvTDM systems.Signal pre-processing module forms each frame in for auxiliary It is synchronous receive digital signal sequences, as illustrated, the signal pre-processing module may include synchronization unit 210, channel estimation list Member 220 and digitlization processing unit 230.
Synchronization unit 210 is used for the docking collection of letters number and forms sign synchronization in time domain, to keep synchronous regime with system, mainly Including Timing Synchronization and carrier synchronization.Synchronously complete the rear docking of channel estimating unit 220 collection of letters number and do channel estimation, for estimating Count the parameter of actual transmission channel.Digitized processing unit 230 is used to be digitized processing to the reception signal of each frame in, So as to form the reception digital signal sequences that suitable Sequence Detection part carries out Sequence Detection.
After pre-processing, the docking collection of letters number a Sequence Detection can be carried out in sequence detection module 300, to the ripple received Shape is cut according to waveform transmission time interval and enters row decoding to the waveform after cutting according to certain decoding algorithm.Fig. 3 is shown The block diagram of the receiving terminal sequence detection module of OvTDM systems.As illustrated, sequence detection module 300 may include analysis storage Unit 310, comparing unit 320 and surviving path memory cell and Euclidean distance memory cell 330.In detection process, point Analysis memory cell makes the complex convolution encoding model and trellis structure of OvTDM systems, and lists whole states of OvTDM systems, And store.Trellis structure of the comparing unit in analysis memory cell, is searched out with receiving data signal minimum Eustachian distance Path, and surviving path memory cell and Euclidean distance memory cell are then respectively used to store the surviving path of comparing unit output With Euclidean distance or weighted euclidean distance.Surviving path memory cell and Euclidean distance memory cell are needed for each stable shape State respectively prepares one.Surviving path memory cell length can be preferably 4K~5K.Euclidean distance memory cell is preferably only to deposit Store up relative distance.
Fig. 4 shows the modulation module block diagram of the transmitting terminal of OvFDM systems.The OvFDM modulation modules of transmitting terminal may include Modulate carrier spectrum generation unit 410, carrier spectrum shift unit 420, multiplication unit 430, adder unit 440 and Fourier Leaf inverse transformation block 450.
First, the envelope frequency spectrum signal H (f) of one subcarrier of generation is designed by modulation carrier spectrum generation unit 410, is carried The envelope frequency spectrum signal H (f) successively frequency displacement specific carriers spectrum intervals Δ B is drawn next height by wave frequency spectral shift bit location 420 The envelope frequency spectrum signal of carrier wave, and by the envelope frequency spectrum signal frequency shift Δ B of next subcarrier, goes down to obtain successively between frequency spectrum It is divided into the spectrum waveform H (f-i × Δ B) of Δ B all subcarriers.
Multiplication unit 430 is by the symbol X for the multidiameter delay to be sentiCorresponding with generation each subcarrier frequency respectively Compose waveform H (f-i × Δ B) to be multiplied, obtain spectrum modulation signal X of the multichannel Jing Guo corresponding subcarrier-modulatediH(f-i×ΔB)。
The multiplexing signal spectrum formed is overlapped by adder unit 440, forms the frequency spectrum of complex modulated signalFinally, the frequency spectrum of the complex modulated signal of generation is entered by Fourier inverse transformation unit 450 The discrete Fu Shi inverse transformations of row, ultimately form the complex modulated signal Signal (t) of time domainTX=ifft (S (f)).
The receiving terminal of OvFDM systems is broadly divided into signal pre-processing module 500 and signal detection module 600.Fig. 5 is shown The block diagram of the signal pre-processing module of the receiving terminal of OvFDM systems.As illustrated, pretreatment module may include synchronization unit 510th, channel estimating unit 520 and digitlization processing unit 530.
Synchronization unit 510 is used for the docking collection of letters number and forms sign synchronization in time domain, to keep synchronous regime with system, mainly Including Timing Synchronization and carrier synchronization.Synchronously complete the rear docking of channel estimating unit 520 collection of letters number and do channel estimation, for estimating Count the parameter of actual transmission channel.Digitized processing unit 530 is used to take the interval reception signal of each symbol time Sample and quantization, are allowed to be changed into digital signal sequences.
After pre-processing, the collection of letters number can be docked in signal detection module 600 to be detected.Fig. 6 shows OvFDM systems The block diagram of the signal detection module 600 of the receiving terminal of system.As illustrated, signal detection module 600 may include Fourier transform list Member 610, frequency segmentation unit 620, convolutional encoding unit 630 and data detecting unit 640.Fourier transformation unit 610 is used In the time-domain signal by pretreatment is converted into frequency domain signal, i.e., to the interval reception data signal sequence of each time symbol Row carry out Fourier transform to form the actual receipt signal frequency spectrum that each time symbol is interval.Frequency segmentation unit 620 is used for The interval actual receipt signal frequency spectrum of each time symbol is segmented in frequency domain with spectrum intervals Δ B, actual reception signal is formed Fragmented spectrum.Convolutional encoding unit 630 is used for one a pair formed between receipt signal frequency spectrum and the data symbol sequence of transmission It should be related to.Data detecting unit 640 is used for the one-to-one relationship according to the formation of convolutional encoding unit, detects data symbol sequence Row.
It is described above the processing procedure for sending and receiving end of OvTDM systems and OvFDM systems.Although above-mentioned OvTDM System and OvFDM systems have corresponding reception demodulation scheme and done to exclude signal in time domain or the overlapping brought of frequency domain Disturb, but the reception greatly improved still to signal of the availability of frequency spectrum proposes requirements at the higher level.
The not only overlapping system of two kinds of overlapping systems above, from the viewpoint of parallel encoding, various multiplexing technologies Such as time division multiplexing tdm, frequency division multiplexing FDM and orthogonal frequency division multiplex OFDM, physics space division multiplexing SDM, statistics space division multiplexing MIMO Deng, be also to belong to encoding constraint length L=1, code check be higher than 1, encoder matrix is only column matrix, code element be only correspondence Time domain, frequency domain, spatial domain etc., input data can make the special case of the simple linear code multiplexing of any modulated signal.
The present invention further provide a kind of OvCDM systems (Overlapping Code Division Multiplexing, Overlapping code division multiplexing), OvCDM can regard a kind of complex field convolutional code in parallel as, its systems function diagram as shown in Figure 19, Corresponding coder structure is as shown in Figure 20.The key of OvCDM systems is encoder matrix, i.e. convolution spreading coefficient, general logical The larger matrix of all Euclidean distances of computer search is crossed as encoder matrix, the arrangement of its encoder matrix is as follows：
Using the system of the above, and corresponding encoder matrix, OvCDM cataloged procedures are as described below：
Data to be sent are turned into the data flow on K sub-data streams, the i-th tunnel by serioparallel exchange and are designated as ui=ui,0ui, 1ui,2....During such as K=2, u0=u0,0u0,2u0,4..., u1=u1,1u1,3u1,5...
Each circuit-switched data one shift register of feeding is weighted superposition, the weight coefficient on the i-th tunnel is bi=bi, 0bi,1bi,2..., it is a complex vector.
Each road signal is added and exported.
Final OvCDM encoders are output as c=c0c1c2...,
OvCDM code check isWherein n is sub-data flow length.When n is very long, by shift register The brought code check loss of hangover can be ignored, and then have rOvCDM≈k。
Compare traditional two element field convolutional encoding model code check and be generally less than 1, cause loss of spectral efficiency.And complex field Convolutional encoding code check is equal to 1, and the convolutional encoding extension of single channel will not cause loss of spectral efficiency, can also increase extra coding and increase Benefit.
Project training sequence is required in general communication system, it is acted on mainly after signal is received by processing, Timing Synchronization, carrier synchronization and channel estimation can be realized simultaneously.Timing Synchronization, carrier synchronization and channel estimation are that receiving terminal is correct The three most important links received.Therefore, the design of training symbol is most important, especially for this superelevation of OvCDM systems The communication system of spectrum efficiency is especially true.If either step error is larger in these three steps, the influence to whole system Will be very big, follow-up decoding process is also just nonsensical.
Current communication system is training sequence frequently with M sequence, because M sequence auto-correlation and cross correlation are poor, is led Cause system synchronization procedure success rate is low, and network insertion is slow.Fig. 7 shows the autocorrelation performance of M sequence, as we can see from the figure its Pulse can all occur in autocorrelation performance separated in time, and its autocorrelation performance is not fine.Therefore in signal processing In, it is poor to the synchronization accuracy of time and frequency, the success rate and access speed of user access network are reduced, becomes Consumer's Experience Difference.
According to an aspect of the present invention, LAS code project training sequences are utilized in OVCDM systems.It has been investigated that, LAS It is zero everywhere beyond preferable impulse function, origin that there is code auto-correlation function, which to be in origin, and cross-correlation function is zero everywhere Characteristic.This is and its favourable attribute for training sequence.In the relevant treatment of follow-up training sequence, by OvCDM code division overlapped signal carries out related processing.
LAS (Large Area Synchronized, large area synchronous) code is a series of 0 value by pulses and Length discrepancy Pulse spacing constitutes, and can be expressed as (N, K, L), wherein N represents pulse number, K represents the most short gap length between pulse, L represents code length.Pulse is generated by complete complementary orthogonal, and its feature is that auto-correlation function is preferable impulse function in origin, It is zero everywhere beyond origin, and cross-correlation function is zero everywhere.It is applied to using this feature of LAS codes in OvCDM systems, it is right There is preferable performance improvement in the synchronous success rate and access speed of whole system.
The generation method of LAS codes is introduced briefly below.
Complete complementary orthogonal has a duality relation, generation method be solved according to most short basic mutual-complementing code it is complete therewith The most short basic mutual-complementing code of another pair of orthogonal complement.With basic short code in present case +++-generate complete complementary orthogonal, it is raw It is as follows into process：
C0=[1 1], are corresponded to ++, S0=[1-1], correspond to+-, according to C0And S0Its mutual-complementing code C is obtained respectively1With S1。C1For to S0Negate and obtain, S1For to C0Negating and asking to be arrived, and code is expressed as in matlab：
C1=fliplr (S0), S1=-1*conj (fliplr (C0)).Wherein fliplr is that matrix is carried out along vertical axis The function of left and right upset, conj is to seek complex conjugate function.
C is tried to achieve accordingly1=[- 1 1], S1=[- 1-1], by C0C1The new mutual-complementing code of combination producing is C0'=[1 1-1 1], S0'=[1-1-1-1], now the length of each mutual-complementing code extends to 4 by 2.
Here the length L of mutual-complementing code can be designedN(LNPower side for 2), i.e. CnAnd SnLength be respectively LN/2.Using The above method, is iterated to the LAS codes of generation, its length is extended for into LN, iterations is log2LN- 2, ultimately generate Mutual-complementing code is Cn、Sn。
By this to mutual-complementing code and null sequence combination producing LAS codes, representation is：Las=[Cn L0 Sn], wherein L0Table Show 0 number, i.e. CnAnd SnBetween most short gap length, the LAS code lengths ultimately generated are expressed as L=LN+L0。
Fig. 8 shows the autocorrelation performance of LAS codes.
According to an aspect of the present invention, LAS codes are employed and carry out project training sequence.
For the purposes of Timing Synchronization, training sequence includes at least one LAS code.Because LAS short codes are larger in frequency deviation In the case of still have preferable synchronous effect, therefore, more preferably, training sequence include at least one LAS short code, with [Xlas]SNTable Show, the length of the wherein LAS short codes is designated as SN, its complementary code length and null sequence length is expressed as LShort-N、LShort -0, SN=LShort-N +LShort -0。
In order to further optimize the autocorrelation performance of LAS codes, it may also include before the LAS short codes and the LAS short code phases With a null sequence of length, with [0]SNRepresent.
In specific embodiment, training sequence may include two identical LAS short codes, and so a LAS short code can wherein In the case of for Timing Synchronization, LAS short codes pair can also be constituted with another LAS short codes, for carrier synchronization.
For the purposes of carrier synchronization, training sequence may include at least one pair of identical LAS codes.Because LAS short codes are in frequency Still there is preferable synchronous effect in the case of partially larger, therefore, more preferably, it is short that training sequence includes at least one pair of identical LAS Code.
More preferably, carrier synchronization can be divided into the thick synchronous and carrier wave of two stages, i.e. carrier wave carefully synchronously.Therefore, sequence is trained Row may include at least two pairs LAS codes.More preferably, a pair of LAS codes can be slightly synchronous for carrier wave for identical LAS short codes, in addition A pair of LAS codes can be identical LAS long codes, carefully synchronous for carrier wave.LAS long codes can use [Xlas]LNRepresent, wherein the LAS length The length of code is designated as LN, and its complementary code length and null sequence length is expressed as LLong-N、LLong -0, LN=LLong-N+LLong -0。
In order to further optimize the cross correlation of LAS codes, it may also include before each LAS short codes and LAS short code phases With a null sequence of length, with [0]SNRepresent.
For the purposes of channel estimation, training sequence may include at least one LAS code, such as one LAS long code, or, Two LAS long codes are may also comprise, twice of channel estimation are done for the two long LAS codes, so as to improve the success rate of channel estimation.
As particular example, L can be designedLong-N=256, LLong -0=16；LShort-N=16, LShort -0=8.Certainly, LAS length here The length of code and LAS short codes is only shown as example, may be designed as other length.
It is a kind of while meeting the LAS codes training of Timing Synchronization, carrier synchronization and channel estimation as preferably embodiment Sequence may be designed as：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN.In this embodiment, first LAS code For short code, Timing Synchronization can be achieved, LAS short codes are in the larger synchronous effect still having had of frequency deviation.First and second LAS short code Slightly synchronous available for carrier wave, the benefit of short code is can to handle larger frequency deviation.Most latter two LAS code is long code, available for thin Correcting frequency deviation and channel estimation.
Timing synchronization procedure
Receiver receives signal, it is necessary to first keep synchronous with communication system, including Timing Synchronization and carrier synchronization.Timing is same The principle of step is, by matched filtering method, will directly to receive signal and seek auto-correlation computation with local LAS codes, obtain self correlated peak Value.The position of training symbol is found according to certain method from correlation peak.The position for finding training symbol is also determined that The original position of present frame, that is, complete the time synchronized for receiving signal and system, and timing synchronization procedure terminates.
As previously described, because the auto-correlation and cross correlation of LAS codes are all relatively good, LAS codes are accorded with for project training Number.Thus, when calculating the related operation for receiving signal and LAS codes, peak value size distribution differs greatly, by reasonably setting Threshold value, can accurately find the original position of LAS codes very much, and timing accuracy is higher.
It is specific, according to training symbol structure, to take suitable signal to receive length when finding the correlation peak of LAS codes, Using sliding window method auto-correlation computation mode, signal will be received and ask related operation to find autocorrelation peak to determine with local LAS codes The position of LAS codes.For example, signal reception length here, which can ensure at least to cover, LAS codes, to guarantee to detect peak value.
So-called sliding window method auto-correlation computation, is that the docking collection of letters number takes window to handle by length of window of the length of LAS codes, This segment signal in current window and local LAS codes are made into related operation, so as to obtain an autocorrelation result.Then, will Window is slided backward, then dock the collection of letters a number progress take window, this segment signal in current window and local LAS codes are remake related Computing, so as to obtain a correlated results again.In this way, continuous sliding window, until all being carried out to the signal received Related operation.From the whole autocorrelation results calculated, by setting threshold value, i.e. the autocorrelation result conduct more than threshold value Peak value, finds the position of LAS codes.
In one example, only include LAS code in training sequence, such as one LAS short code because short code frequency deviation compared with Still there is preferable synchronous effect in the case of big.In this case, it is possible to regard the length of the LAS short codes as length of window pair Receiving signal takes window to handle, and this segment signal in current window and local LAS short codes is made into related operation, so as to obtain one Individual autocorrelation result.Then, window is slided backward, then docks a collection of letters number progress and take window, by this segment signal in current window Related operation is remake with local LAS codes, so as to obtain a correlated results again.In this way, continuous sliding window, until right The signal received has all carried out related operation.From the whole autocorrelation results calculated, by setting threshold value, that is, exceed The autocorrelation result of threshold value finds the position of LAS codes as peak value.
In the case of multipath channel, it is possible to which the amplitude for several footpaths below occur exceeds the amplitude in first footpath, it should Choosing exceedes first peak point of threshold value, and is not necessarily global maximum.Fig. 9 shows the autocorrelation result of Timing Synchronization Distribution map.Assuming that threshold value is 100, as shown in figure 9, the autocorrelation result more than threshold value 100 there are two, but 25 positions are chosen at Autocorrelation result as this computing peak value, so as to regard this as the position of the LAS codes found in 25 position.
In previous preferably training symbol format [0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LNFeelings Under condition, there are two LAS short codes in training sequence.Now, two can be found out by above-mentioned sliding window autocorrelation calculation method to exceed The peak value of threshold value.Fig. 9 shows the distribution map of the autocorrelation result in the presence of two peak values.At this time, it may be necessary to judge which be The peak value of preceding short code, which is the peak value in rear short code.
Figure 10 shows the schematic diagram for detecting the training sequence under two peak value situations.Figure 10 illustrates repeat to follow Two training sequences that ring is sent.Two training sequences of length spans of signal are received, therefore, two peak values found out may One of them is due to caused by first LAS short code of next training sequence.So needing to judge each peak value institute Which LAS short code corresponding be.
Specifically, if two peak intervals length are 2*SN, then it is the to choose first to exceed the peak value of threshold value The original position of one short LAS codes, if both gap lengths are more than 2*SN, second peak value for exceeding threshold value is first The original position of individual short LAS codes.
If there is multipath channel, then two part integrated distribution relevant peaks occur after sliding window, to the phase of every part Guan Feng is compared with threshold value respectively, chose first peak point of threshold value, two will be obtained after two parts are completeer and is exceeded The point of threshold value, the position of correspondence LAS codes is determined further according to method as above.
In addition, if transmission signal have passed through other band limiting filters, then it is peak more smooth one by one after matched filtering, Rather than independent point, so needing to choose peak point according to actual band limiting filter.
Figure 11 shows the block diagram of the time synchronization unit of receiving terminal according to an aspect of the present invention.The Timing Synchronization Unit can be the part above in association with Fig. 2 and Fig. 5 synchronization unit discussed.
As shown in figure 11, time synchronization unit 1100 may include autocorrelation calculation unit 1110 to perform auto-correlation meter Calculate.The autocorrelation calculation unit 1110 can carry out taking window to the signal received, to use local LAS codes to the letter in window Number make autocorrelation calculation, and slide the window to carry out autocorrelation calculation next time, until reaching that signal receives length.Timing is same Step unit 1100 may also include peak value judging unit 1120, and the position of peak value is judged for the correlated results set according to acquisition Put, to find the original position of LAS codes.Peak value judging unit 1120 can choose suitable threshold value, by more than the auto-correlation of threshold value As a result as peak value.
Figure 12 shows the flow chart of time synchronization method according to an aspect of the present invention.As illustrated, this method can Including：
Step 1201：The signal received is carried out taking window, to make from phase the signal in window using local LAS codes Close and calculate, and slide the window to carry out autocorrelation calculation next time, until reaching that signal receives length；And
Step 1202：The position of peak value is judged according to the correlated results set of acquisition, to find the start bit of LAS codes Put.
As described above, in the case where there are two LAS short codes, if two peak intervals length are 2*SN, then choosing The original position that first peak value for exceeding threshold value is first short LAS codes is taken, if both gap lengths are more than 2*SN, Second peak value for exceeding threshold value is the original position of first short LAS codes.
Carrier synchronization process
Receive after signal, it is necessary to first with communication system holding synchronization, including Timing Synchronization and carrier synchronization, receive signal Synchronization with the system first retention time, the original position of LAS codes is obtained by Timing Synchronization, then enter the synchronization of line frequency.
For carrier synchronization, receiving the training sequence message part of signal includes at least one pair of identical LAS codes.To repeating LAS codes carry out computing cross-correlation, obtain frequency deviation f.
Assuming that the carrier deviation between receiver and emitter be Δ f, the AD sampling interval be T, then receiving terminal, which is ignored, makes an uproar When acoustical signal influences, the signal received is expressed as：
yn=xnej2πΔfnT
The coefficient correlation of former and later two LAS codes is：
Wherein L represents the interval between LAS codes.
From above formula, carrier wave frequency deviation is：
More preferably, training sequence message part may include two pairs of LAS codes, wherein, a pair of identical LAS codes are LAS short codes, It is possible thereby to which it is slightly synchronous first to carry out carrier wave；Include a pair of identical LAS long codes again in addition, it is possible thereby to which it is carefully synchronous to carry out carrier wave.
Due to having been completed Timing Synchronization, the training symbol index that can be returned according to Timing Synchronization extracts corresponding two The short LAS codes in part, carrier wave are carried out to short LAS codes slightly synchronously, short code can handle larger frequency deviation, be calculated according to above-mentioned formula Frequency deviation value to estimation is Δ f1.Then the long LAS codes of two parts are extracted again, and the thin correcting frequency deviation of carrier wave is carried out to long LAS codes, obtained Frequency deviation value to estimation is Δ f2, with reference to thick synchronous frequency deviation, then the frequency deviation of final output is Δ f=Δs f1+Δf2。
With previous preferably training symbol format [0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LNFor Example.LN=272, SN=24 are made, training symbol total length is 640.Two short LAS are respectively (25:48) with (73:96) two positions Put, long LAS code divisions are not (97:368) with (369：640) two positions.
Ideally, the original position that Timing Synchronization calculates obtained LAS codes is the start bit of first short LAS codes Put, as 25.It is corresponding from signal is received to extract corresponding code according to this index and the code length LN and SN of long short code.
Carrier wave is slightly synchronous
The short LAS codes of two parts are extracted from signal is received, according to formulaConjugate multiplication is asked to it, obtained To coefficient R.Further according to formulaObtain corresponding thick frequency deviation Δ f1, wherein L represents two short Interval between LAS codes, the L=2*SN=48 it can be seen from training symbol structure.
Thick frequency deviation according to calculating passes through formulaDocking, which is collected mail, number carries out a frequency offset correction, obtains the Signal after frequency offset correction.
The thin frequency offset correction of carrier wave
The docking collection of letters number has carried out thick frequency offset correction in the thick synchronization of carrier wave, obtains receiving signal yn'.Thin frequency deviation process be from yn' in extract the long LAS codes of two parts, according to formulaConjugate multiplication is asked to it, coefficient R is obtained.Again According to formulaObtain corresponding thin frequency deviation Δ f2, L represents the interval between two long LAS codes, by Training symbol structure can be seen that L=LN=272.
With reference to thick synchronous frequency deviation, then the frequency deviation of final output is Δ f=Δs f1+Δf2.And according to formula yn"=yn'ej2 π(-Δf)nTObtain the signal after the thin correcting frequency deviation of the docking collection of letters number.
By the signal y after frequency offset correction twicen" as input signal to channel estimation process, carrier synchronization process terminates.
Figure 13 shows the block diagram of carrier synchronization unit 1300.The carrier synchronization unit 1300 can be above in association with Fig. 2 With a part for Fig. 5 synchronization units discussed.
As illustrated, carrier synchronization unit 1300 may include cross-correlation calculation unit 1310 and frequency correction unit 1320. Cross-correlation calculation unit 1310 can perform cross-correlation calculation to obtain carrier wave between receiving terminal and transmitting terminal to a pair of LAS codes Frequency deviation.Frequency correction unit 1320 can be according to the frequency deviation of the carrier wave, and docking, which is collected mail, number performs a frequency offset correction.
In one embodiment, the cross-correlation calculation of a pair of LAS short codes can be first carried out in cross-correlation calculation unit 1310, to obtain Obtain the thick frequency deviation of carrier wave between receiving terminal and transmitting terminal.Frequency correction unit 1320 can be first according to the thick frequency deviation, the docking collection of letters number Perform first frequency offset correction.Cross-correlation calculation unit 1310 again to from by first frequency offset correction reception signal extracted one Cross-correlation calculation is performed to LAS long codes, to obtain the thin frequency deviation of carrier wave between receiving terminal and transmitting terminal.Frequency correction unit 1320 Secondary frequency offset correction can be performed to the reception signal through first frequency offset correction, further according to the thin frequency deviation and the thick frequency deviation to obtain Signal after final frequency offset correction.
Figure 14 shows the flow chart of the carrier synchronization method according to an embodiment.As illustrated, carrier synchronization method can Comprise the following steps：
Step 1401：To from the two LAS codes execution cross-correlation for receiving signal extraction, with obtain receiving terminal and transmitting terminal it Between carrier wave frequency deviation；And
Step 1402：A frequency offset correction is performed based on the frequency deviation docking collection of letters number.
Figure 15 shows the flow chart of the carrier synchronization method according to another embodiment.As illustrated, carrier synchronization method It may include following steps：
Step 1501：To performing cross-correlation from two LAS short codes for receiving signal extraction, to obtain receiving terminal and transmitting terminal Between carrier wave thick frequency deviation；
Step 1502：According to the thick frequency deviation, the docking collection of letters number performs a first frequency offset correction；
Step 1503：Cross-correlation meter is performed to a pair of the LAS long codes extracted from the reception signal through first frequency offset correction Calculate, to obtain the thin frequency deviation of carrier wave between receiving terminal and transmitting terminal；And
Step 1504：According to the thin frequency deviation and the thick frequency deviation, secondary frequency is performed to the reception signal through first frequency offset correction Correction partially.
Although for make explanation simplify the above method is illustrated and is described as a series of actions, it should be understood that and understand, The order that these methods are not acted is limited, because according to one or more embodiments, some actions can occur in different order And/or with from it is depicted and described herein or herein it is not shown and describe but it will be appreciated by those skilled in the art that other Action concomitantly occurs.
Channel estimation process
Channel estimation is used for the transmission characteristic for estimating channel, i.e., channel is to the influence of the signal transmitted.By using hair Training symbol known to sending end and receiving terminal both sides, receiving terminal can be according to the known training symbol and the training received Symbol performs channel estimation.For example, receiving terminal can be held to known training symbol and the training symbol received Row is related, so that it is determined that the transmission characteristic of channel.After channel estimation is carried out, receiving terminal can be estimated using identified channel Count to demodulate the unknown data signal received, to determine the actual data signal of transmitting terminal transmission.
Receive signal and pass through Timing Synchronization, and system hold time synchronization.Then carrier synchronization is done with reception signal again, carried Ripple synchronously includes thick synchronous and thin synchronous, by the synchronous carrier wave frequency deviation Δ f for obtaining receiver and transmitter, passes through carrier frequency The signal of reception is corrected partially, revised reception signal y is obtainedfix, to yfixDo channel estimation.
The present invention is using LAS codes as training sequence, such as long LAS codes L-LAS in training symbol format is available for believing Estimate in road.
Channel estimation is represented by：
Wherein ynRepresent to pass through the revised reception signal of carrier synchronization, i.e. yfix.N represents LAS code lengths.xnRepresent local LAS codes, i.e. xnIt is expressed as most one of latter two long LAS code in training symbol.R0The quadratic sum of LAS codes is represented, P represents multipath Channel number.
Reception signal y of the channel estimator from training symbolfixThe impulse response h (t) of middle estimation channel, then according to estimating The h (t) that counts out constructs an inverse channel system, and the data-signal received, which passes through after the inverse channel system, to be reduced into pair Transmitting terminal is fed to the estimation of the signal of channel.
It is general to receive signal ynIt can be expressed asenRepresent noise.Substituted into above formula expansion After obtain equation below：
The auto-correlation of training sequence is represented, is zero by rationally designing auto-correlation coefficient, estimation channel height Close to real channel, so as to drastically increase the precision of channel estimation.According to the present invention, because LAS codes auto-correlation occurs 0 Probability is high, therefore substantially increases the success rate of channel estimation when carrying out channel estimation.
This area typically carries out channel estimation using M sequence.The autocorrelation performance of M sequence as shown in Figure 7, can from figure To see that pulse can all occur in its autocorrelation performance separated in time, its autocorrelation performance is not fine, respective channels estimation Formula
InValue is not very big for 0 probability, Therefore the channel model and ideal communication channel model bias estimated is larger, influences very big for follow-up decoding processing, improves The bit error rate of system.
LAS code sequences are contrasted, there is auto-correlation function to be to be everywhere beyond preferable impulse function, origin in origin for it Zero, and cross-correlation function is the characteristics of be zero everywhere, therefore when doing channel estimation, channel model and preferable mould that actual estimated goes out Type deviation very little, reduces the bit error rate of system, and good improvement has been obtained to systematic function.
According to the present invention, because long LAS codes have two in training symbol, therefore channel estimation process can be using wherein Any one long LAS code is realized, or can also do twice of channel estimation for the two long LAS codes, is estimated so as to improve channel The success rate of meter.
A channel or multipath channel may be present in a communication environment, receiver can determine whether there is many according to environment Footpath channel.In the case of no multipath channel, i.e. p=0 can directly calculate channel estimation h according to above formula.And it is many having In the case of the channel of footpath, the channel estimation value h of every multiple paths can be calculated respectively according to above formulap, wherein many for every Footpath path is by local LAS codes xnEnter line displacement, the deviation of each paths can be 1.
For example, actual multipath channel can be such as 6.Local LAS codes are arranged in 6 according to multipath number first Row, the deviation in each row path is 1, and arrangement mode is as shown in Figure 16.
According to training symbol format [0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN, from revise signal yfix In find corresponding LAS code positions, and extract as yfix-las, common two parts.
By the y extractedfix-lasPass through formula with the local LAS codes of 6 multipath channels after rearranging respectively
After processing, the channel estimation value h of every multiple paths is obtainedp.Due to altogether There are two parts LAS codes to carry out channel estimation, can all obtain channel estimation value h per part after treatmentp, two parts are asked Average value then can obtain the channel estimation value h of every last multiple pathsp。
Then, can the channel estimation value h based on every multiple pathspTo demodulate the data-signal received, so as to obtain extensive Appear again the transmission end signals of every multiple paths.
Project training sequence frequency range
Design symbols structure includes training sequence TSC (traning sequence code) and data in the system (data).The design of training symbol is most important, and the timing, synchronization, channel estimation three that have impact on whole system are most important Link, if either step error is larger in these three steps, the decoding process that the influence to whole system will be very big, follow-up Also it is just nonsensical.
The design process of training sequence frequency range is complex, and its corresponding power spectral density is larger when frequency range is shorter, when being The reception and transmission of data can be influenceed when there is multiple carrier waves in system, corresponding power spectral density is too small when frequency range is excessive, to being The transmitter of system and the sensitivity requirement of receiver are high.
It is general using training sequence and the frequency range identical method of data, its corresponding power in existing communication system Spectrum density is identical, and due in General System frequency range it is all shorter, therefore corresponding to time domain send the time it is longer, influence signal it is same Step, channel estimation process time course, the follow-up decoding process stand-by period are also elongated, reduce the transmission rate of system.In addition, Because the training sequence transmission time is longer, therefore when being sampled to signal, its sample rate is relatively low, and temporal resolution is not smart enough Carefully, the deviation of channel estimation is influenceed.
Data bandwidth (for example, 5 times, 10 times, 15 times or more) is much larger than the invention enables training sequence frequency range, so as to instruct The power spectral density for practicing sequence is less than the power spectral density of data, its training sequence, the frequency range of data and power spectral density relation Figure is as shown in Figure 17.Because the transmit power of training sequence and data need to be consistent, as can be seen from Figure, when training sequence After the frequency range of row broadens, its corresponding power spectral density can consequently also be greatly lowered, for data power spectral density It is very low.
The system can use all available spreading codes, including m-sequence, Golomb codes, CAN (Cyclic Algorithm New) and LAS codes etc..We introduce by taking the LAS codes with complete complementary orthogonal property as an example in the system The processing procedure of Timing Synchronization, carrier synchronization and channel estimation.Therefore, it is previously described to be carried out using LAS codes as midamble code Timing Synchronization, carrier synchronization, all method and devices of channel estimation are also applied for all suitable spreading codes as midamble code It is timed synchronization, carrier wave and training estimation.Therefore, above using LAS codes as the Timing Synchronization exemplified, carrier synchronization and channel The algorithm of estimation is merely possible to shown in example, and the above of the invention is applied to all suitable midamble codes.
The characteristics of LAS codes be auto-correlation function be in origin be zero everywhere beyond preferable impulse function, origin, it is and mutual Close function be everywhere the autocorrelation performance of zero, LAS codes as shown in Figure 8.Therefore also will not mutually it be made when training sequence is overlapping Into interference.So design can improve the availability of frequency spectrum and transmission rate of system.
By formulaUnderstand, when frequency domain frequency range is bigger, its correspondence is smaller in time of time domain, i.e., when shorter In can just complete training sequence send and receive process.Process is received in signal, for the data of same length, when connecing Shorten, the sample rate of signal can be improved so that temporal resolution is finer between time receiving.The time is improved in channel estimation process The accuracy of resolution ratio so that channel estimation results are more accurate.
On the one hand, because the power spectral density of training sequence is extremely low, influence hardly is produced on data-signal, therefore Training sequence and data can be superimposed in the same time to be sent.In other words, training sequence and data be frequency and/or time up to What small part was overlappingly sent.When have two carrier signals and meanwhile send data when, its structural map as shown in Figure 18, from figure As can be seen that having protection band in the middle of the real data that two carrier waves are carried, overlapping also will not will not mutually it interfere；And instruct Practicing the frequency range and real data of sequence has overlapping, because training sequence power spectral density is very low, therefore will not be to real data Interfere；Further, different training sequences can be distinguish between with different spreading codes, do not result in and obscure.Training sequence is not Specific frequency and time resource are monopolized, the availability of frequency spectrum and transmission rate of system is improved.
In one embodiment, the LAS codes with complete complementary orthogonal property can be used in the system for training sequence, It is zero everywhere beyond preferable impulse function, origin that its feature is in origin for auto-correlation function, and cross-correlation function is everywhere The auto-correlation and cross correlation of zero, LAS code are as shown in Figure 5.Therefore it also will not mutually cause to do when training sequence is overlapping Disturb.So design can improve the availability of frequency spectrum and transmission rate of system.
Our forms of project training sequence are in present case：[0]SN,[Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN, [Xlas]LN。
It will be understood by those skilled in the art that appointing in various different technologies and skill can be used in information, signal and data What technology and skill are represented.For example, above description quote from the whole text data, instruction, order, information, signal, position (bit), Symbol and chip can be by voltage, electric current, electromagnetic wave, magnetic field or magnetic particle, light field or optical particle or its any combinations be come table Show.
Those skilled in the art will further appreciate that, the various illustratives described with reference to the embodiments described herein Logic plate, module, circuit and algorithm steps can be realized as electronic hardware, computer software or combination of the two.To be clear Explain to Chu this interchangeability of hardware and software, various illustrative components, frame, module, circuit and step be above with Its functional form makees vague generalization description.Such feature be implemented as hardware or software depend on concrete application and Put on the design constraint of total system.Technical staff can be realized described for every kind of application-specific with different modes Feature, but such realize that decision-making should not be interpreted to cause departing from the scope of the present invention.
With reference to presently disclosed embodiment describe various illustrative logic modules and circuit can with general processor, Digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other FPGAs Device, discrete door or transistor logic, discrete nextport hardware component NextPort or its be designed to carry out any group of function described herein Close to realize or perform.General processor can be microprocessor, but in alternative, the processor can be any routine Processor, controller, microcontroller or state machine.Processor is also implemented as the combination of computing device, such as DSP One or more microprocessors cooperated with the combination of microprocessor, multi-microprocessor, with DSP core or any other this Class is configured.
It can be embodied directly in hardware, in by processor with reference to the step of the method or algorithm that embodiment disclosed herein is described Embodied in the software module of execution or in combination of the two.Software module can reside in RAM memory, flash memory, ROM and deposit Reservoir, eprom memory, eeprom memory, register, hard disk, removable disk, CD-ROM or known in the art appoint In the storage medium of what other forms.Exemplary storage medium is coupled to processor to enable the processor from/to the storage Medium is read and write-in information.In alternative, storage medium can be integrated into processor.Processor and storage medium can Reside in ASIC.ASIC can reside in user terminal.In alternative, processor and storage medium can be as discrete Component is resident in the user terminal.
In one or more exemplary embodiments, described function can be in hardware, software, firmware or its any combinations It is middle to realize.If being embodied as computer program product in software, each function can be used as the instruction of one or more bars or generation Code storage is transmitted on a computer-readable medium or by it.Computer-readable medium includes computer-readable storage medium and communication Both media, it includes any medium for facilitating computer program to shift from one place to another.Storage medium can be can quilt Any usable medium that computer is accessed.It is non-limiting as example, such computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage apparatus can be used to carry or store instruction Or the desirable program code and any other medium that can be accessed by a computer of data structure form.Any connection is also by by rights Referred to as computer-readable medium.If for example, software is to use coaxial cable, fiber optic cables, twisted-pair feeder, digital subscriber line Or the wireless technology of such as infrared, radio and microwave etc is passed from web site, server or other remote sources (DSL) Send, then the coaxial cable, fiber optic cables, twisted-pair feeder, DSL or such as infrared, radio and microwave etc is wireless Technology is just included among the definition of medium.Disk (disk) and dish (disc) as used herein include compact disc (CD), laser disc, laser disc, digital versatile disc (DVD), floppy disk and blu-ray disc, which disk (disk) are often reproduced in the way of magnetic Data, and dish (disc) laser reproduce data optically.Combinations of the above should also be included in computer-readable medium In the range of.
It is for so that any person skilled in the art all can make or use this public affairs to provide of this disclosure be previously described Open.Various modifications of this disclosure all will be apparent for a person skilled in the art, and as defined herein general Suitable principle can be applied to spirit or scope of other variants without departing from the disclosure.Thus, the disclosure is not intended to be limited Due to example described herein and design, but it should be awarded and principle disclosed herein and novel features phase one The widest scope of cause.

Claims (22)

1. a kind of signal processing method, including：
Perform pretreatment to the reception signal from transmitting terminal, the reception signal be the code division overlapped signal from transmitting terminal and Including training sequence and data based on midamble code, wherein training sequence frequency range is more than the power of data bandwidth and training sequence Spectrum density is less than the power spectral density of data, and the execution pretreatment includes：
Pretreatment is performed to the reception signal using the training sequence based on midamble code.
2. signal processing method as claimed in claim 1, it is characterised in that described using the training sequence based on midamble code Row perform pretreatment to the reception signal includes at least one of：
Timing Synchronization is performed to the reception signal using the training sequence based on midamble code；
Carrier synchronization is performed to the reception signal using the training sequence based on midamble code；Or
Channel estimation is performed to the reception signal using the training sequence based on midamble code.
3. signal processing method as claimed in claim 1, it is characterised in that the midamble code include m-sequence, Golomb codes, CAN codes or LAS codes.
4. signal processing method as claimed in claim 1, it is characterised in that the training sequence frequency range is more than data bandwidth 5 times, 10 times, 15 times or more.
5. signal processing method as claimed in claim 2, it is characterised in that it is short that the training sequence includes at least one LAS Code [Xlas]SN, SN is the length of the LAS short codes, and the training sequence based on midamble code described in is to the reception signal Performing pretreatment includes：
Timing Synchronization is performed to the reception signal using at least one described LAS short code.
6. signal processing method as claimed in claim 5, it is characterised in that it is short that the training sequence includes two LAS Code, it is described that the reception signal execution pretreatment is also included using the training sequence based on midamble code：
Carrier synchronization is performed to the reception signal using described two LAS short codes.
7. signal processing method as claimed in claim 6, it is characterised in that the training sequence includes：[0]SN,[Xlas]SN, [0]SN,[Xlas]SN, wherein [0]SNFor 0 sequence that length is SN.
8. signal processing method as claimed in claim 7, it is characterised in that the training sequence also includes two LAS long codes [Xlas]LN, LN is the length of the LAS long codes, described that the reception signal is held using the training sequence based on midamble code Row pretreatment also includes：
Using described two LAS long codes to the secondary execution carrier synchronization of the reception signal Jing Guo carrier synchronization.
9. signal processing method as claimed in claim 8, it is characterised in that described using the training sequence based on midamble code Row perform pretreatment to the reception signal also to be included：
Channel estimation is performed to the reception signal through carrier synchronization using any one of described two long LAS codes.
10. signal processing method as claimed in claim 8, it is characterised in that described using the training based on midamble code Signal is received described in sequence pair and performs to pre-process also includes：
Channel estimation twice is performed to the reception signal through carrier synchronization using described two long LAS codes.
11. signal processing method as claimed in claim 8, it is characterised in that the training sequence includes：[0]SN,[Xlas]SN, [0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN, wherein [0]SNFor 0 sequence that length is SN.
12. a kind of signal processing apparatus, including：
Pretreatment unit, for performing pretreatment to the reception signal from transmitting terminal, the reception signal is to come from transmitting terminal Code division overlapped signal and including training sequence and data based on midamble code, wherein training sequence frequency range is more than data bandwidth And the power spectral density of training sequence is less than the power spectral density of data, the pretreatment unit is using described based on midamble code Training sequence performs pretreatment to the reception signal.
13. signal processing apparatus as claimed in claim 10, it is characterised in that pretreatment unit includes at least one of：
Time synchronization unit, for performing Timing Synchronization to the reception signal using the training sequence based on midamble code；
Carrier synchronization unit, for performing carrier synchronization to the reception signal using the training sequence based on midamble code； Or
Channel estimating unit, for performing channel estimation to the reception signal using the training sequence based on midamble code.
14. signal processing apparatus as claimed in claim 12, it is characterised in that the midamble code includes m-sequence, Golomb Code, CAN codes or LAS codes.
15. signal processing apparatus as claimed in claim 12, it is characterised in that the training sequence frequency range is more than data bandwidth 5 times, 10 times, 15 times or more.
16. signal processing apparatus as claimed in claim 13, it is characterised in that the training sequence includes at least one LAS Short code [Xlas]SN, SN is the length of the LAS short codes, and the pretreatment unit includes the time synchronization unit, the timing Synchronization unit is further used for performing Timing Synchronization to the reception signal using at least one described LAS short code.
17. signal processing apparatus as claimed in claim 16, it is characterised in that the training sequence includes two LAS Short code, the pretreatment unit also includes the carrier synchronization unit, and the carrier synchronization unit is further used for using described Two LAS short codes perform carrier synchronization to the reception signal.
18. signal processing apparatus as claimed in claim 17, it is characterised in that the training sequence includes：[0]SN, [Xlas]SN,[0]SN,[Xlas]SN, wherein [0]SNFor 0 sequence that length is SN.
19. signal processing apparatus as claimed in claim 16, it is characterised in that the training sequence also includes two LAS length Code [Xlas]LN, LN is the length of the LAS long codes, and the carrier synchronization unit is further used for using described two LAS long codes To the secondary execution carrier synchronization of the reception signal Jing Guo carrier synchronization.
20. signal processing apparatus as claimed in claim 19, it is characterised in that the pretreatment unit also includes the channel Estimation unit, the channel estimating unit is further used for using any one of described two long midamble codes to through carrier synchronization Reception signal perform channel estimation.
21. signal processing apparatus as claimed in claim 19, it is characterised in that the pretreatment unit also includes the channel Estimation unit, the channel estimating unit is further used for using described two long midamble codes to the reception signal through carrier synchronization Perform channel estimation twice.
22. signal processing apparatus as claimed in claim 19, it is characterised in that the training sequence includes：[0]SN, [Xlas]SN,[0]SN,[Xlas]SN,[Xlas]LN,[Xlas]LN, wherein [0]SNFor 0 sequence that length is SN.
CN201610219190.5A 2016-04-08 2016-04-08 Signal processing method and system Active CN107276627B (en)

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