CN1809045A - Combined time synchronization method for receiving end of WiMAX system base station - Google Patents
Combined time synchronization method for receiving end of WiMAX system base station Download PDFInfo
- Publication number
- CN1809045A CN1809045A CN 200510130341 CN200510130341A CN1809045A CN 1809045 A CN1809045 A CN 1809045A CN 200510130341 CN200510130341 CN 200510130341 CN 200510130341 A CN200510130341 A CN 200510130341A CN 1809045 A CN1809045 A CN 1809045A
- Authority
- CN
- China
- Prior art keywords
- timing
- mrow
- msub
- synchronization
- sample
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 22
- 238000005070 sampling Methods 0.000 claims description 15
- 125000004122 cyclic group Chemical group 0.000 claims description 10
- 238000013461 design Methods 0.000 claims description 8
- 238000012935 Averaging Methods 0.000 claims description 6
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims description 3
- 230000036961 partial effect Effects 0.000 abstract 1
- 238000006243 chemical reaction Methods 0.000 description 10
- 239000000969 carrier Substances 0.000 description 7
- 238000012937 correction Methods 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 239000013256 coordination polymer Substances 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- 238000009795 derivation Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005562 fading Methods 0.000 description 2
- 108010076504 Protein Sorting Signals Proteins 0.000 description 1
- ODKSFYDXXFIFQN-UHFFFAOYSA-M argininate Chemical compound [O-]C(=O)C(N)CCCNC(N)=N ODKSFYDXXFIFQN-UHFFFAOYSA-M 0.000 description 1
- 230000021615 conjugation Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Images
Landscapes
- Synchronisation In Digital Transmission Systems (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
This invention relates to simultaneous method to receive locking simultaneous timing collection used in microwave to take global WiMAX system station receive end, which comprises the following steps: determining OFDM character initial point; timing the FFT changed front radio frequency zone sequence with known short radio zone sequence to get range angle sequence ok; through ok front and back sequence values; then taking even sequence by minus to get beta; then beta times -256/2pi; controlling frame simultaneous and sample timing according to the results integral and partials.
Description
Technical Field
The invention relates to a combined timing synchronization optimization method for frame, symbol fine synchronization and sampling timing synchronization at a receiving end of a base station of a WiMAX (worldwide interoperability for microwave Access) system in the communication field.
Background
In recent years, as mobile operators, equipment manufacturers, mobile phone manufacturers and government departments of all countries in the world invest considerable funds and energy for the construction and operation of 3 rd generation mobile communication networks (3G), the computer industry has introduced a new broadband wireless access technology and named WiMAX. WiMAX is an abbreviation for Worldwide Interoperability for microwave Access, which is commonly translated into "Worldwide Interoperability for microwave Access".
WiMAX technology is based on the 802.16 series of standards of IEEE. In the 802.16 series standard, the technical requirements of the air interface between the base station bs (base station) and the subscriber station ss (subscriber station) are specified in detail, and particularly, the frame structure requirements of the physical layer, the system design parameters, and the like are specified in detail. The invention is mainly designed for timing synchronization of a receiving end of a WiMAX system (IEEE 802.16-2004) base station based on an OFDM physical layer.
OFDM, an abbreviation of Orthogonal Frequency Division Multiplex, in chinese, means Orthogonal Frequency Division multiplexing. The OFDM technology is based on orthogonal multiple carriers, which is a multi-carrier spread spectrum technology. The great advantage of OFDM is against frequency selective fading or narrow-band interference, which can cause the entire communication link to fail in a single carrier system, but only a small fraction of the carriers are disturbed in a multi-carrier system, and error correction codes can be used for these sub-channels for error correction. In the OFDM system, the carriers of each sub-channel are orthogonal to each other, and the frequency spectrums are overlapped with each other, so that the mutual interference among the sub-carriers is reduced, and the frequency spectrum utilization rate is improved.
In the design of WiMAX system based on OFDM, the requirement for synchronization is quite high in order to ensure orthogonality between subcarriers. Once out of synchronization, orthogonality between subcarriers is affected, thereby severely affecting system performance. Therefore, the superiority and inferiority of the synchronization algorithm can lead to the performance of the whole system. A high-performance and practical synchronization algorithm is designed, and becomes a key link of the whole system design.
The synchronization algorithm includes time domain synchronization and frequency domain synchronization. Frame synchronization is a precondition and a basis for the whole WiMAX system to correctly receive data. The physical layer of the 802.16-2004 protocol based on the OFDM mode supports frame-based transmission. One frame includes one downlink subframe and one uplink subframe. The downlink subframe consists of one downlink physical layer PDU and the uplink subframe consists of contention slots for initial search and bandwidth request purposes and one or more uplink physical layer bursts transmitted by different SSs. The Burst of each uplink SS contains a short preamble.
The downlink physical layer PDU is started by a long preamble for physical layer synchronization. The uplink physical layer PDU (protocol data unit) is started by a short preamble for synchronization of uplink bursts.
An OFDM symbol is a useful symbol time T from the time domainbAnd length T of cyclic prefix CPgSum Ts. The CP is a copy of the length of the end of the useful symbol time to collect multipath and maintain the orthogonality of the subcarriers. The length of the CP should be greater than the maximum multipath delay length. The OFDM symbol is shown in fig. 1.
According to the stipulation of the protocol, the value of the uplink short lead code in the frequency domain sequence of the WiMAX system based on OFDM is determined by the following formula:
whereinThe factor is related to the 3dB gain. PALLThe frequency domain sequences are uniformly specified by the protocol and have fixed values. Thus, the preamble received by the base station to the SS (subscriber station) appears in the time domain as two repetitions of 128 samples, preceded by the cyclic prefix of the preamble. As shown in fig. 2.
According to the design of practical system, the base station receives bursts of physical layer of the up-going SS (subscriber station), it must first detect the short preamble in front of the Burst of each SS for frame timing synchronization, and only after detecting the preamble, the base station can receive and process the data Burst.
In an actual WiMAX system, a data processing flow chart at the receiving end of a base station is shown in fig. 3. The upper part of the figure is the data flow of the transmitter and the lower part is the data flow of the receiver. The transmitter performs serial/parallel conversion on the data after modulation processing (constellation mapping), performs IFFT conversion, performs parallel/serial conversion on the converted data, inserts cyclic prefix, windowing and digital-to-analog conversion (DAC), and transmits the data to a wireless communication environment through radio frequency. The receiver is the inverse process of the transmitter and mainly comprises the steps of radio frequency receiving, analog-to-digital conversion (ADC), cyclic prefix removing, serial/parallel conversion, FFT demodulation and the like.
According to the basic principle of OFDM, when multicarrier transmission is performed by using OFDM, the requirement of the base station receiving end on synchronization is quite high in order to correctly receive the transmitted data symbols and improve the performance of the system. The synchronization process at the receiving end of the WiMAX base station is shown in fig. 4.
Disclosure of Invention
The invention aims to provide a combined timing synchronization method for frame timing fine synchronization and sample timing synchronization at a receiving end of a base station of a Worldwide Interoperability for Microwave Access (WiMAX) system.
The invention provides a combined timing synchronization method for frame timing fine synchronization and sample timing synchronization at the receiving end of a base station of a Worldwide Interoperability for Microwave Access (WiMAX) system, which comprises the following steps: performing time domain frame coarse synchronization before Fast Fourier Transform (FFT) according to a short preamble of a known sequence transmitted by an SS (service State) transmitting end, and determining a starting point of an OFDM (orthogonal frequency division multiplexing) symbol; the short leading frequency domain sequence after FFT is subjected to conjugate multiplication with the known short leading frequency domain sequence, and then the argument is taken to obtain the argument sequence alphak(ii) a By mixing alphakSubtracting the values of the preceding and following sequences, and averaging all the subtracted sequences to obtainβ, and then multiplying β by-256/2 π, to control frame timing synchronization and sample timing synchronization based on the integer and fractional portions of the result.
The method can effectively reduce the influence of carrier frequency phase deviation, corrected carrier frequency, sampling frequency residual error, random noise and the like on frame timing synchronization and sample timing synchronization, improves the synchronization timing precision, accelerates the speed of the WiMAX system for completing the synchronization timing, and reduces the system delay caused by the synchronization timing.
Drawings
FIG. 1: an OFDM symbol schematic diagram;
FIG. 2: a frame short preamble time domain structure;
FIG. 3: a data processing flow chart of a receiving terminal of a WIMAX system base station;
FIG. 4: a synchronous flow chart of a receiving end of a WiMAX system base station;
FIG. 5: an OFDM symbol diagram that takes into account sample timing and symbol timing offsets;
FIG. 6: the invention relates to a flow chart of a combined algorithm of frame timing fine synchronization and sample timing synchronization of a WiMAX system base station.
Detailed Description
The invention provides a joint synchronization method for frame, symbol timing and sampling timing of a receiving end of a base station of a WiMAX system, which has the following basic principle:
let the expression of the SS transmit signal be: x (t) ej(2πfct+*)Wherein x (t) is the waveform of SS transmitting terminal after D/A conversion, fcTo transmit the carrier frequency, * is the carrier phase.
After passing through the transmission channel, the signals at each point at the receiving end of the base station can be represented as:
wherein,frequency and phase estimates are estimated for the carrier. Δ fcΔ * is the carrier frequency offset and phase offset, and η (t) is the channel noise.
Obtaining a data stream of r after samplingn}，
Wherein,for the purpose of the sampling interval estimation,
fourier FFT is carried out, and r isnSubstituting the expression of (1) into (2) for simplification to obtain:
(1-3)
wherein,
are all due to interference caused by noise, SmAnd m, N and k are 0, 1, 2 … … and N-1 for the frequency domain sequence before IFFT transformation at the SS sending end.
If the timing deviation deltat of the upper sample is considered againy(corresponding to the reception signal y (t) in <math> <mrow> <mi>t</mi> <mo>=</mo> <mi>n</mi> <msub> <mover> <mi>T</mi> <mo>^</mo> </mover> <mi>s</mi> </msub> <mo>-</mo> <mi>Δ</mi> <msub> <mi>t</mi> <mi>y</mi> </msub> </mrow> </math> Sampling at a moment to obtain rn(ii) a Reconsidering the presence of symbol timing deviation Δ tfEquivalent to following from the cyclic prefix <math> <mrow> <mi>Δ</mi> <msub> <mi>n</mi> <mi>f</mi> </msub> <mo>=</mo> <mi>Δ</mi> <msub> <mi>t</mi> <mi>f</mi> </msub> <mo>/</mo> <msub> <mover> <mi>T</mi> <mo>^</mo> </mover> <mi>s</mi> </msub> </mrow> </math> The FFT operation is performed for the first N samples of the sample. Here we assume Δ nf，ΔtfTaking a value of positive means leading the optimum symbol sample timing; a negative value indicates a lagging optimum symbol sample timing.
An OFDM symbol that takes into account sample timing offset and symbol timing offset is shown in fig. 5.
The output signal after FFT demodulation at the receiving end while comprehensively considering the carrier synchronization deviation, the sample synchronization deviation, and the symbol synchronization deviation is:
(1-4)
as can be seen from the above formula, only Δ fc，ΔTsNot only causes the phase of the signal to deflect, but also changes the amplitude of the signal, bringing about the reduction of the signal-to-noise ratio (SNR). Other deviations Δ *, Δ ty，ΔnfAnd noise etc. only cause the signal phase to deflect without affecting the signal amplitude.
For the convenience of analysis, the product term between various deviations is considered to be small, and after the product term is ignored, the following formula can be simplified:
wherein
Indicating interference of other subcarriers with the desired carrier.
First term on right side of equation (1-5)I.e. the desired data symbol term, the second term is the effect on the desired symbol caused by the symbols transmitted on the other subcarriers. It is due to carrier frequency deviation, carrier phase deviation, sample frequency deviation, sample timing deviation, symbol timing deviation, noise, etc. that the desired data symbols are passed through the coefficients Ik，kWeighting and interference on other sub-carriers.
In the practical WiMAX system, after the initial sample and symbol coarse synchronization, the frequency offset fine synchronization and the channel estimation and correction, Δ f is not considered for the moment for the convenience of analysisc、ΔTsThe simplified equation (1-5) can now be:
it follows that, assuming that the phase deviation of the received signal with respect to the transmitted signal is α, then
α＝-2πkΔty/(NTs)-2πkΔnf/N-Δ*-α′ (1-7)
Where α' is the phase deflection due to noise, with some randomness. The simplification (1-7) can obtain:
α＝-2πk[Δty/(NTs)+Δnf/N]-Δ*-α′ (1-8)
through analysis, the phase deviation caused by the first term on the right side of the expression (1-8) is in direct proportion to the subcarrier number k, the phase deviation of the second term on the right side is the same for all subcarriers, namely, the second term is a quantity which is independent of the carrier number k, and the third term on the right side is the phase deviation caused by other factors such as noise and the like, and the phase deviation has certain randomness.
Aiming at the analysis, the invention provides a combined algorithm of fine timing synchronization and sample value deviation timing synchronization at a receiving end of a base station of a WiMAX system, which comprises the following steps:
and (one) performing time domain frame coarse synchronization before FFT transformation according to a short preamble of a known sequence transmitted by a SS transmitting end, and determining a starting point nO of the OFDM symbol (the coarse synchronization can be determined by performing delay correlation through 128 repeated samples of the short preamble and by an output peak value of a correlator).
(II) the frequency domain sequence value R of the short preamble receiving signal sequence after the FFT transformation after the frequency offset correction and the channel estimationk(k is 0, 1, … … 255) and the known short preamble frequency domain sequence value are subjected to conjugate multiplication to obtain an intermediate variable Rk′＝RkSk *In which S isk *Represents a pair SkTaking conjugation, taking Rk' the argument yields the sequence value αk＝arg(Rk'), (k ═ 0, 1, … … 255), where arg () denotes the argument.
(III) taking betak＝αk+1-αk(k-0, 1, … … 254), converting the sequence β into a sequence βkTaking an average to obtain <math> <mrow> <mover> <mi>β</mi> <mo>‾</mo> </mover> <mi></mi> <mo>=</mo> <mi></mi> <mfrac> <mn>1</mn> <mn>255</mn> </mfrac> <munderover> <mi>Σ</mi> <mrow> <mi>k</mi> <mo>=</mo> <mn>0</mn> </mrow> <mn>254</mn> </munderover> <msub> <mi>β</mi> <mi>k</mi> </msub> </mrow> </math> Taking the intermediate variable theta-256 beta/2 pi, the integer part of theta is delta nfThe fractional part is Δ ty/TsAccording to Δ ny、ΔtyAs a result, the OFDM time domain frame timing and sample timing before FFT conversion are controlled, thereby achieving precise timing synchronization and sample timing synchronization for OFDM symbols.
The flow chart of the present invention is shown in fig. 6 (the flow of frequency offset synchronization, channel estimation, etc. is omitted in the figure).
The algorithm is further described below with reference to the algorithm flow chart of fig. 6:
firstly, the WiMAX base station performs analog/digital conversion on the received signal sent by the uplink SS, performs frame timing coarse synchronization (the synchronization method may adopt delay correlation to find the maximum value) through the time domain structure feature of the uplink preamble (the uplink preamble is an OFDM symbol, the front is a cyclic prefix, and then two 128 sample sequences are repeated), and determines the coarse timing synchronization point n0 as the start position of the preamble.
According to the result of frame coarse synchronization timing, we can remove the cyclic prefix sample according to the CP length specified by the system, and perform FFT fourier transform on the OFDM valid data to obtain the frequency domain sequence value of the preamble symbol (note that before and after FFT, it is necessary to perform frequency offset correction and channel estimation according to the result of coarse timing synchronization to complete necessary signal processing and correctly receive signals).
Since the protocol specifies the frequency domain sequence value of the SS short preamble symbol of the WiMAX system, the received short preamble frequency domain sequence value is multiplied by the conjugate of the known frequency domain sequence complex value, Rk′＝RkSk *From the previous derivation, we can derive the intermediate variable Rk′，RkThe magnitude of' will be the square of the modulus of the known short preamble frequency domain complex sequence, and its phase will be the sum of the phase deviations due to the various deviations. Including a timing symbol deviation deltan proportional to the subcarrier number kfAnd the sampling timing deviation Δ tyThe phase deviation caused by the carrier frequency is not related to the subcarrier frequency offset number k, and the carrier frequency is not related to the subcarrier frequency offset number k.
By applying to an intermediate variable RkTaking the amplitude angle, we obtain the total deviation sequence alpha of the received short preamble frequency domain sequence caused by various deviationsk(k is 0, 1, … 255), and then alpha is addedkSubtracting the sequence value from the sequence value to obtain another intermediate variable sequence betak＝αk+1-αk(k-0, 1, … 254). By the foregoing derivation, weIt can be seen that through the process of this subtraction, various phase deviations caused by various synchronization deviations, which are independent of the subcarrier number k, including the phase deviation caused by the carrier phase deviation Δ *, the residual carrier frequency deviation, the sample frequency deviation, and so on, can be effectively eliminated.
Then beta is mixedkAveraging over all sub-carriers of the whole preamble we get <math> <mrow> <mover> <mi>β</mi> <mo>‾</mo> </mover> <mi></mi> <mo>=</mo> <mfrac> <mn>1</mn> <mn>255</mn> </mfrac> <mi></mi> <munderover> <mi>Σ</mi> <mrow> <mi>k</mi> <mo>=</mo> <mn>0</mn> </mrow> <mn>254</mn> </munderover> <msub> <mi>β</mi> <mi>k</mi> </msub> <mo>,</mo> </mrow> </math> By this averaging process, random fluctuations of the phase deviation α' caused by various random deviations, mainly random phase deviations caused by various noises, can be effectively eliminated. It is known that one advantage of multi-carrier systems is that they are efficient against frequency selective fading, since only a part of the sub-carriers are affected by noise. This averaging of the phase deviations is also very resistant to random phase shifts caused by random noise.
After processing by the foregoing processes, we obtain a phase offset value that is substantially related only to timing symbol offset and sample timing offset <math> <mrow> <mover> <mi>β</mi> <mo>‾</mo> </mover> <mo>=</mo> <mfrac> <mn>1</mn> <mn>255</mn> </mfrac> <munderover> <mi>Σ</mi> <mrow> <mi>k</mi> <mo>=</mo> <mn>0</mn> </mrow> <mn>254</mn> </munderover> <msub> <mi>β</mi> <mi>k</mi> </msub> <mo>=</mo> <mo>-</mo> <mn>2</mn> <mi>π</mi> <mo>[</mo> <mi>Δ</mi> <msub> <mi>t</mi> <mi>y</mi> </msub> <mo>/</mo> <mrow> <mo>(</mo> <mi>N</mi> <msub> <mi>T</mi> <mi>s</mi> </msub> <mo>)</mo> </mrow> <mo>+</mo> <mi>Δ</mi> <msub> <mi>n</mi> <mi>f</mi> </msub> <mo>/</mo> <mi>N</mi> <mo>]</mo> <mo>,</mo> </mrow> </math> Where Δ tyIs less than TsError term of, Δ nfIs an error term with integer value, in the WiMAX system, N is 256, TsA constant, representing the sampling time interval, is taken according to the system design, as the inverse of the sampling frequency. Then we multiply β by-256/2 π to get Δ ty/Ts+ΔnfWherein the integer part is Δ nfThe fractional part is Δ ty/TsBy multiplying the fractional part by TsCan obtain Δ tyThe value of (a).
From the previous analysis, we have derived from Δ nfReturning to the step of removing the control cyclic prefix before FFT conversion to obtain accurate timing synchronization according to delta tyThe value of (2) can control the synchronization of the sample timing. Of course, according to the actual system design requirement, in order to reduce the influence of the delay of the system on the performance of the system, the delay can also be based on Δ nfAnd Δ tyTo control cyclic prefix removal and sample timing synchronization of the next OFDM symbol. In particular, if Δ nfTaking a positive value to indicate frame timing advance optimum timing Δ nfCoarse synchronization timing n0 should be delayed by an amount of Δ nfTaking the sample value as a frame synchronization timing point; if Δ nfA value of negative indicates an optimum timing deltan of the frame timing lagfSample number, coarse synchronization timing n0 should be extended forward by anfThe samples serve as frame sync timing points. For Δ tyWith the same operation if Δ tyTaking the value as positive, delaying the sampling moment backward by delta ty(ii) a If Δ tyTaking the value as negative, extending the sampling moment by delta ty。
The traditional timing fine synchronization algorithm is based on pilot frequency carrier waves to carry out accurate timing synchronization, and compared with the traditional fine timing synchronization algorithm, the timing fine synchronization algorithm has the advantages that: based on the short preamble symbol sent by the uplink SS, accurate frame and symbol fine timing synchronization and sample value timing synchronization are carried out on the basis of frame and symbol coarse synchronization, the synchronization timing process of the system is accelerated, and the synchronization timing precision is improved. Meanwhile, according to the design principle of the algorithm, the algorithm has strong resistance to carrier frequency phase fixed deviation and phase random deviation caused by noise, and the anti-interference capability of timing synchronization is improved.
Claims (6)
1. A joint timing synchronization method for fine frame timing synchronization and sample timing synchronization at the receiving end of a base station of a Worldwide Interoperability for Microwave Access (WiMAX) system is characterized by comprising the following steps:
a) performing time domain frame coarse synchronization before Fast Fourier Transform (FFT) according to a short preamble of a known sequence transmitted by an SS (service State) transmitting end, and determining a starting point of an OFDM (orthogonal frequency division multiplexing) symbol;
b) the short leading frequency domain sequence after FFT is subjected to conjugate multiplication with the known short leading frequency domain sequence, and then the argument is taken to obtain the argument sequence alphak；
c) By mixing alphakSubtracting the two sequence values, averaging all the subtracted sequences to obtain beta, multiplying beta by-256/2 pi, and controlling frame timing synchronization and sample timing synchronization according to the integer and fractional parts of the obtained result.
2. The method of claim 1, wherein: alpha in said step c)kSubtracting the front and back sequence values and then averaging to obtain <math> <mrow> <mover> <mi>β</mi> <mo>‾</mo> </mover> <mo>=</mo> <mfrac> <mn>1</mn> <mn>255</mn> </mfrac> <munderover> <mi>Σ</mi> <mrow> <mi>k</mi> <mo>=</mo> <mn>0</mn> </mrow> <mn>254</mn> </munderover> <mrow> <mo>(</mo> <msub> <mi>α</mi> <mrow> <mi>k</mi> <mo>+</mo> <mn>1</mn> </mrow> </msub> <mo>-</mo> <msub> <mi>α</mi> <mi>k</mi> </msub> <mo>)</mo> </mrow> <mo>,</mo> </mrow> </math> (k＝0，1，......254)。
3. The method according to claim 1 or 2, characterized in that: the integer part of the result in step c) is the frame timing offset, the fractional part is multiplied by TsIs a sample timing offset, where TsIs a constant taken according to the system design, representing the sampling time interval, which is the inverse of the sampling frequency.
4. The method of claim 3, wherein: alpha is alphakIs the total deviation sequence of the received short preamble frequency domain sequence caused by various deviations, wherein k is 0, 1.
5. The method of claim 4, wherein: cyclic prefix removal and sample timing synchronization of the next Orthogonal Frequency Division Multiplexing (OFDM) symbol may be controlled based on the values of the frame timing offset and the sample timing offset.
6. The method according to claim 5, wherein said controlling of frame timing synchronization and sample timing synchronization in step c) comprises the steps of: if the frame timing deviation is positive and Δ nfIndicates the frame timing advance optimum timing DeltanfSample, should delay the coarse synchronization timing backward by anfTaking the sample value as a frame synchronization timing point; if Δ nfA value of negative indicates an optimum timing deltan of the frame timing lagfSample number, should extend the coarse synchronization timing forward by anfTaking the sample value as a frame synchronization timing point; synchronizing Δ t to sample timingyIf Δ t isyTaking the value as positive, delaying the sampling moment backward by delta ty(ii) a If Δ tyTaking the value as negative, extending the sampling moment by delta ty。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200510130341A CN100576835C (en) | 2005-12-12 | 2005-12-12 | A kind of combined time synchronization method that is used for WiMAX system base-station receiving terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200510130341A CN100576835C (en) | 2005-12-12 | 2005-12-12 | A kind of combined time synchronization method that is used for WiMAX system base-station receiving terminal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1809045A true CN1809045A (en) | 2006-07-26 |
| CN100576835C CN100576835C (en) | 2009-12-30 |
Family
ID=36840736
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200510130341A Active CN100576835C (en) | 2005-12-12 | 2005-12-12 | A kind of combined time synchronization method that is used for WiMAX system base-station receiving terminal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100576835C (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009082953A1 (en) * | 2007-12-25 | 2009-07-09 | Huawei Technologies Co., Ltd. | Transmission method, system and device of synchronous channel |
| WO2010054546A1 (en) * | 2008-11-12 | 2010-05-20 | 深圳华为通信技术有限公司 | Synchronization method, base station, network server and communication system |
| CN101400141B (en) * | 2008-10-15 | 2010-06-09 | 中兴通讯股份有限公司 | Method and system for keeping data channel synchronization in WIMAX service |
| CN101222471B (en) * | 2008-02-04 | 2010-08-11 | 北京北方烽火科技有限公司 | Base band link scaling method suitable for IEEE802.16e base station receiver |
| CN101282261B (en) * | 2007-04-03 | 2011-10-26 | 中兴通讯股份有限公司 | Evolvement system being compatible with variable bandwidth Wimax system, wireless frame as well as generating method thereof |
| CN101282258B (en) * | 2007-04-04 | 2011-12-07 | 中兴通讯股份有限公司 | Evolvement system being compatible with variable frequency range Wimax system, frame as well as generating method thereof |
| CN101374131B (en) * | 2007-08-20 | 2013-01-30 | 株式会社Ntt都科摩 | Method and apparatus of timing synchronization, leading symbol as well as method and apparatus for generating the same |
| CN102984112A (en) * | 2012-11-30 | 2013-03-20 | 南通大学 | Synchronizing method of high-speed mobile OFDM (orthogonal frequency division multiplexing) system |
| CN103152294A (en) * | 2013-02-27 | 2013-06-12 | 北京福星晓程电子科技股份有限公司 | Method and system for estimating noise based on signal elimination |
| CN101232365B (en) * | 2006-10-05 | 2013-08-14 | 马维尔国际贸易有限公司 | Mobile communication device and burst checking method used therebetween |
| CN105960820A (en) * | 2014-10-31 | 2016-09-21 | 华为技术有限公司 | Synchronization device and method |
| CN115001919A (en) * | 2022-04-13 | 2022-09-02 | 北京理工大学 | Timing synchronization construction method and system of SEFDM (subscriber identity distribution framework) system |
-
2005
- 2005-12-12 CN CN200510130341A patent/CN100576835C/en active Active
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101232365B (en) * | 2006-10-05 | 2013-08-14 | 马维尔国际贸易有限公司 | Mobile communication device and burst checking method used therebetween |
| CN101282261B (en) * | 2007-04-03 | 2011-10-26 | 中兴通讯股份有限公司 | Evolvement system being compatible with variable bandwidth Wimax system, wireless frame as well as generating method thereof |
| CN101282258B (en) * | 2007-04-04 | 2011-12-07 | 中兴通讯股份有限公司 | Evolvement system being compatible with variable frequency range Wimax system, frame as well as generating method thereof |
| CN101374131B (en) * | 2007-08-20 | 2013-01-30 | 株式会社Ntt都科摩 | Method and apparatus of timing synchronization, leading symbol as well as method and apparatus for generating the same |
| WO2009082953A1 (en) * | 2007-12-25 | 2009-07-09 | Huawei Technologies Co., Ltd. | Transmission method, system and device of synchronous channel |
| CN101222471B (en) * | 2008-02-04 | 2010-08-11 | 北京北方烽火科技有限公司 | Base band link scaling method suitable for IEEE802.16e base station receiver |
| CN101400141B (en) * | 2008-10-15 | 2010-06-09 | 中兴通讯股份有限公司 | Method and system for keeping data channel synchronization in WIMAX service |
| WO2010054546A1 (en) * | 2008-11-12 | 2010-05-20 | 深圳华为通信技术有限公司 | Synchronization method, base station, network server and communication system |
| CN102984112B (en) * | 2012-11-30 | 2015-04-15 | 南通大学 | Synchronizing method of high-speed mobile OFDM (orthogonal frequency division multiplexing) system |
| CN102984112A (en) * | 2012-11-30 | 2013-03-20 | 南通大学 | Synchronizing method of high-speed mobile OFDM (orthogonal frequency division multiplexing) system |
| CN103152294A (en) * | 2013-02-27 | 2013-06-12 | 北京福星晓程电子科技股份有限公司 | Method and system for estimating noise based on signal elimination |
| CN103152294B (en) * | 2013-02-27 | 2016-08-31 | 北京晓程科技股份有限公司 | The method and system carrying out noise estimation are eliminated based on signal |
| CN105960820A (en) * | 2014-10-31 | 2016-09-21 | 华为技术有限公司 | Synchronization device and method |
| CN105960820B (en) * | 2014-10-31 | 2019-05-24 | 华为技术有限公司 | A kind of synchronizing device and method |
| CN115001919A (en) * | 2022-04-13 | 2022-09-02 | 北京理工大学 | Timing synchronization construction method and system of SEFDM (subscriber identity distribution framework) system |
| CN115001919B (en) * | 2022-04-13 | 2023-12-05 | 北京理工大学 | Timing synchronization construction method and construction system of SEFDM system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100576835C (en) | 2009-12-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1809045A (en) | Combined time synchronization method for receiving end of WiMAX system base station | |
| CN1277359C (en) | Method for estimating carrier, frequency shifts of orthogonal FDM communication system | |
| KR101109939B1 (en) | Channel estimation with effective co-channel interference suppression | |
| CN1988526B (en) | Synchronizing method for multiple input multiple output orthogonal frequency division multiplex radio system | |
| KR100736062B1 (en) | Correction of a sampling frequency offset in an orthogonal frequency division multiplexing system | |
| CN1798123A (en) | Apparatus and method for estimating uplink frequency offset in a orthogonal frequency division multiplexing communication system | |
| CN101079688A (en) | A synchronization method in orthogonal frequency division multiplexing system | |
| CN101336522A (en) | Apparatus and method for carrier frequency synchronization in an OFDM system | |
| CN1630283A (en) | Method of transmitting preamble for synchronization in a MIMO-OFDM system | |
| KR20060054651A (en) | Apparatus and method for acquiring synchronization in a mobile communication system using an orthogonal frequency division multiplexing scheme | |
| CN1881970A (en) | Method and apparatus for compensating sampling frequency offset and carrier frequency offset in OFDM system | |
| CN1527513A (en) | Information processing method and device using time domain pilot sequence in OFDM system | |
| CN101064700A (en) | Method for synchronization of multi-input multi-output OFDM system | |
| CN1346186A (en) | Equipment and method for compensation frequency shift in orthogonal FDMS | |
| CN1172467C (en) | Apparatus and method for compensating frequency shift in orthogonal frequency division multiple system | |
| CN1885846A (en) | Orthogonal frequency-division multiplexing system and selective mapping transmitting and receiving method | |
| CN100369394C (en) | Method for carrying out frame synchronization timing at receiving and of base station of WiMAX system | |
| CN1674467A (en) | Data transmitting method in short-distance radio network | |
| CN1574821A (en) | TDS-OFDM receiver and signal processing method thereof | |
| CN101075829A (en) | Method for estimating channel of orthogonal frequency-division multiplexing system | |
| CN1921361A (en) | Channel estimation method, frequency tracking method and multi-carrier receiver | |
| CN100499622C (en) | OFDM time and frequency synchronization method | |
| CN101299735B (en) | Method and system for estimating carrier frequency migration | |
| CN1753395A (en) | Symbol timing method for multi-antenna wireless communication system | |
| CN1291561C (en) | Method for obtaining rough estimate of frequency diviation by frequency domain PV sequence guidance |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20200123 Address after: 430073 Hubei province Wuhan Dongxin East Lake high tech Development Zone, Road No. 5 Patentee after: Wuhan Hongxin Telecommunication Technologies Co.,Ltd. Address before: 100085, beacon building, No. 5-3, East Road, Beijing, Haidian District Patentee before: Beifang Fenghuo Tech Co., Ltd., Beijing |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20200630 Address after: 430074 Wuhan, Hongshan Province District Road, Department of mail, No. 88 hospital Patentee after: Wuhan Feng and Zhida information technology LLC Address before: 430073 Hubei province Wuhan Dongxin East Lake high tech Development Zone, Road No. 5 Patentee before: Wuhan Hongxin Telecommunication Technologies Co.,Ltd. |