CN102035779B - Demodulation module, signal analysis device and signal analysis method - Google Patents
Demodulation module, signal analysis device and signal analysis method Download PDFInfo
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Abstract
The invention discloses a demodulation module, a signal analysis device and a signal analysis method. The signal analysis device comprises a relativity calculating device, a symbol boundary detection device and a carrier frequency shift estimation device. The relativity calculating device is used for receiving an input signal, delaying the input signal according to a plurality of different retardation to obtain a plurality of delayed signals, calculating the relativity of the delayed signals and a prearranged virtual noise sequence to obtain a plurality of relativity calculated results, and generating a relativity sequence according to the relativity calculated result. The symbol boundary detection device is used for detecting a sample point with a maximal relativity according to the relativity sequence, and generating a symbol boundary indication signal according to a relativity numerical value of the sampling point. The carrier frequency shift estimation device is used for estimating the carrier frequency shift quantity according to the symbol boundary indication signal.
Description
Technical field
The present invention relates to a kind of method of estimation of carrier frequency drift, particularly relate to a kind of carrier frequency drift method of estimation that is applicable to the multi-path transmission channel.
Background technology
In wireless telecommunication system, because concussion frequency inaccuracy and Doppler effect (Doppler Effect), thereby between transmission end and receiving terminal, may produce the problem of carrier frequency drift (Carrier Frequency Offset, be called for short CFO).Especially in OFDM (Orthogonal frequency division multiplexing is called for short OFDM) system, the impact that the carrier frequency drift produces is even more serious.Because the transmission system of OFDM is multicarrier system, very responsive for the carrier frequency drift, carrier frequency drift meeting destroys the orthogonality between the ofdm system sub-carriers, thereby caused between subcarrier and interfered with each other (Inter-Carrier Interference, be called for short ICI) so that problems such as the system effectiveness variation of ofdm system and the rate increases that makes a mistake.Therefore, how exactly the estimating carrier frequency drift interferes with each other (ICI) and becomes the important topic that the ofdm system utmost point need be solved to solve intercarrier.
Summary of the invention
According to one embodiment of the invention, a kind of demodulation module comprises analog-to-digital converter, fundamental frequency frequency mixer, time sequence reply device, signal analysis device and decoder.Analog-to-digital converter is changed an analog if signal, to export a digital medium-frequency signal.The fundamental frequency frequency mixer receives this digital medium-frequency signal, and according to this digital medium-frequency signal of carrier frequency frequency reducing to produce a fundamental frequency signal, wherein this fundamental frequency frequency mixer is also adjusted this carrier frequency according to one first back coupling control signal, to compensate the carrier frequency drift of this carrier frequency.The time sequence reply device is feedback control signal this fundamental frequency signal of resampling according to one second.Signal analysis device receives this fundamental frequency signal, analyze the correlation of this fundamental frequency signal and a predetermined virtual noise sequence to obtain a plurality of correlation results, and strengthen described correlation results producing a correlation sequence, and this first feedbacks control signal and this second feedback signal according to this correlation sequence generation.Decoder is in order to decipher an output signal of this time sequence reply device, to produce a decoding output signal.
According to another embodiment of the present invention, a kind of signal analysis device comprises correlation calculations device, the marginal checkout gear of symbol (symbol) and carrier frequency drift estimation unit.The correlation calculations device receives an input signal, postpone this input signal to obtain a plurality of inhibit signals according to a plurality of different retardations, and calculate the correlation of described inhibit signal and a predetermined virtual noise sequence, obtaining a plurality of correlativity calculation result, and produce a correlation sequence according to described correlativity calculation result.Symbol limit checkout gear has a sampling point of maximum correlation according to this correlation Sequence Detection, and produces symbol limit index signal according to a correlation values of this sampling point.Carrier frequency drift estimation unit is estimated a carrier frequency drift amount according to this symbol limit index signal.
According to another embodiment of the present invention, a kind of signal analysis method comprises: receive an input signal, wherein this input signal comprises a data information and a virtual noise sequence at least; Postpone this input signal according to a plurality of different retardations, to obtain a plurality of inhibit signals; Calculate the correlation of described inhibit signal and a predetermined virtual noise sequence, to obtain a plurality of correlativity calculation result; Produce a correlation sequence according to described correlativity calculation result; And according to a carrier frequency drift amount of this this input signal of correlation sequencal estimation.
Description of drawings
Fig. 1 a-1b shows the data structure of digital television broadcasting data.
Fig. 2 shows the correlation operation result who receives signal in the multi-path transmission channel environment.
Fig. 3 a-3b shows estimation and the corresponding compensation result of carrier frequency drift in the multi-path transmission channel environment.
Fig. 4 shows according to the described receiver of one embodiment of the invention.
Fig. 5 a-5c shows described in the correlativity calculation result of multi-path transmission channel environment according to one embodiment of the invention.
Fig. 6 shows according to the described correlation calculations device of one embodiment of the invention.
Fig. 7 shows according to the described signal analysis method of one embodiment of the invention.
The reference numeral explanation
100,101～data;
201～required;
202～error items;
400～receiver;
401～tuner;
402～demodulation module;
403～analog-to-digital converter;
404～fundamental frequency frequency mixer;
405～time sequence reply device;
406～equalizer;
407～decoder;
408～signal analysis device;
411,611～correlation calculations device;
412～symbol limit checkout gear;
413～sequential mistake estimation unit;
414～carrier frequency drift estimation unit;
612,613～computing module;
621,631,624,634, FIFO～first-in first-out register;
622,632～conjugate complex number unit;
623,633～multiplier;
625,635～correlation calculations unit;
Corr (n), Corr_D1 (n), Corr_D2 (n)～correlation;
D～delay;
Data～data information;
PN, PN code, Pre PN, Post PN～virtual noise sequence;
S-
B, S-
C, S-
IND, S-
OUT, S
RF, S-
T～signal.
Embodiment
For manufacturing of the present invention, method of operation, target and advantage can be become apparent, several preferred embodiments cited below particularly, and be described with reference to the accompanying drawings as follows:
Embodiment:
Digital ground multimedia/television broadcasting (Digital terrestrial multimedia/television broadcasting is called for short DTMB) system is in recent years new development digital television broadcasting system specification out.The technology of DTMB comprises to be inserted known virtual noise (Pseudo Noise, be called for short PN) sequence in the guard interval, in order to the protected data signal, and can be further in order to the original position of Identification Data data.Fig. 1 a-1b shows the data structure of DTMB.As shown in the figure, data 100 and 101 are the data of the DTMB of a frame (frame), and wherein data 101 are that data 100 are postponed the result of D sampling point.Data 100 and 101 comprise respectively the part of PN sequence (being denoted as PN code) and the part of data information (being denoted as Data), wherein PN sequence tail end part can be repeated to make an addition to the head (being denoted as Pre PN) of PN sequence again, and the head of PN sequence can be repeated to make an addition to the tail end (being denoted as Post PN) of PN sequence again.For example, DTMB can use the PN420 specification, wherein can add altogether 420 PN sequence before the data information, comprise 255 complete PN sequences, and adding wherein, 82 first halfs in the PN sequence form Pre PN part, and add wherein at 83 in latter half of the formations Post PN part of PN sequence, so formation length totally 420 sequence.
Because the content of the PN sequence that the known transmission end of receiving terminal inserts, therefore after carrying out the phase multiplication by result's (for example data 101 shown in Figure 1) of the conjugate complex number of the DTMB data that receiver is received (for example data 100 shown in Figure 1) and D sampling point of DTMB data delay, the PN sequence that operation result and receiver local side is stored is carried out the computing of correlation (correlation) again, finds out the sampling point max (Corr with maximum correlation
D(n)), synchronous to reach data information.Wherein, sampling point with maximum correlation is representing the stored PN sequence of local side and is mating the most in this sampling point and the DTMB data that receive, in case the coupling of PN sequence is finished, can obtain receiving the original position of PN sequence in the signal, then, just can go out by the location identification of PN sequence the data information original position, it is synchronous to reach data information.Calculate the example of correlation can be further with reference to by the people such as Ling-Long Dai in November, 2008 at (the Institute of Electrical and Electronic Engineers of the Institute of Electrical and Electronics Engineers, be called for short IEEE) communication system international conference (International Conference on Communications Systems, be called for short ICCS) technical literature delivered, title is " in the time-domain synchronous orthogonal frequency-division multiplexing system new frequency synchronization algorithm " (A new frequency synchronization algorithm in the TDS-OFDM systems).
Except the timing synchronization that reaches data information, receiver can further utilize resulting maximum correlation result of calculation max (Corr
D(n)) estimate the carrier frequency drift Δ f that transmission channel produces, wherein the method for estimation of carrier frequency drift Δ f is as follows:
Wherein fs is a sampling frequency (Fig. 4, the sampling frequency of analog-to-digital converter 403).
Yet, in the transmission channel environment of multi-path (multi-path), because the received signal of receiving terminal can comprise the DTMB data from an above transmission path, therefore when carrying out correlation operation, except required (the Desired term) that should have in theory maximum correlation, also can additionally produce the no small error items of a plurality of correlations (False term), even the correlation of error items and required item are quite or larger.Required the sampling point (having maximum correlation) that mates the most for PN sequence in theory, the result who multiplies each other of the conjugate complex number of the DTMB data that namely receive in theory and the delay version of DTMB data carries out should having after the correlation operation sampling point of maximum correlation again with the PN sequence of local side, representing at this sampling point, PN sequence in the PN sequence of local side and the DTMB data that receive reaches synchronously, and other sampling point then is error items.Fig. 2 shows the correlation operation result who receives signal in the multi-path transmission channel environment, wherein transverse axis represents sampling point, the longitudinal axis represents the result of calculation of correlation, suppose that transmission channel comprises 2 paths, so the result of calculation of correlation should comprise two required items 201 that correlation is stronger in theory.Yet, in case the effect that the correlation of error items 202 produces because of the channel response of multi-path thereby when being higher than required can cause at the sampling point max (Corr that seeks maximum correlation
D(n)) obtain wrong result the time, thus, the data information that not only makes the mistake is synchronous, and the carrier frequency drift estimated result that also leads to errors.
Fig. 3 a-3b is presented at estimation and the corresponding compensation result of carrier frequency drift in the multi-path transmission channel environment, transverse axis representative frame index (frame index) wherein, the longitudinal axis represent according to carry out the as a result Δ f that the carrier frequency drift is estimated suc as formula (1) described method.In more detail, Fig. 3 a is according to required estimating carrier frequency drift, the result who compensates, and Fig. 3 b is according to the drift of error items estimating carrier frequency, the result who compensates.Shown in Fig. 3 a, if can find correct required, the carrier frequency drift Δ f that then can estimate exactly, in this example, frame index is 0 o'clock, is 100kHz according to the carrier frequency drift of required the reality of estimating.Then come compensating carrier frequency according to the carrier frequency drift delta f that estimates, after after a while compensation, can be so that actual carrier frequency drift converges on 0kHz.Yet, if carry out the estimation of carrier frequency drift according to error items, be unable to estimate out actual carrier frequency drift Δ f.That is to say that if the carrier frequency drift Δ f that estimates according to error items compensates, then actual carrier frequency drift then can't converge on 0kHz.Shown in Fig. 3 b, frame index is 0 o'clock, the carrier frequency drift of estimating according to error items is 200kHz (but not actual carrier frequency drift 100kHz), if 200kHz compensates according to this carrier frequency drift, after after a while compensation, so that actual carrier frequency drift is-100kHz, but not converge on 0kHz.In view of this, the present invention proposes a kind of new carrier frequency drift method of estimation accurately to estimate the correct item of demanding, this carrier frequency drift method of estimation is not only applicable to single path transmission channel environment, more be applicable to multi-path transmission channel environment, synchronous in order to accurately to finish data information, and accurately estimate the carrier frequency drift.
Fig. 4 shows according to the described receiver 400 of one embodiment of the invention.Receiver 400 comprises a tuner (tuner) 401 and a demodulation module 402.The RF signal S that tuner 401 will be received by antenna
RFBe converted to the intermediate-freuqncy signal of simulation.Demodulation module 402 can be integrated into a demodulator IC, receives the intermediate-freuqncy signal of simulating in order to self-tuner 401, and this signal of demodulation is to produce output signal S-
OUT(Transport Stream).
According to one embodiment of the invention, demodulation module 402 can comprise analog-to-digital converter (Analog to digital converter is called for short ADC) 403, fundamental frequency frequency mixer 404, time sequence reply device 405, equalizer 406, decoder 407 and signal analysis device 408.Analog-to-digital converter 403 is in order to (formula (1), the fs) intermediate-freuqncy signal of sampling simulation is with the output digital medium-frequency signal according to a sampling frequency.Fundamental frequency frequency mixer 404 carries out the frequency reducing conversion according to a carrier frequency with digital medium-frequency signal, to produce digital baseband signal S
B Signal analysis device 408 is in order to analyze digital baseband signal S
BThe characteristic of middle virtual noise sequence, and produce respectively according to the characteristic of virtual noise sequence and to feedback control signal S
CWith S
TTo fundamental frequency frequency mixer 404 and time sequence reply device 405, wherein fundamental frequency frequency mixer 404 is according to feedbacking control signal S respectively
CThe information that provides changes the frequency of carrier wave, and in order to compensating carrier frequency offset, and time sequence reply device 405 is according to feedbacking control signal S
TThe timing synchronization information that the provides digital baseband signal S that resamples
B, in order to signal is returned back to the sequential synchronous with the transmission end.The output signal of equalizer 406 balanced time sequence reply devices 405 is in order to compensate the frequency response of transmission channel, the impact that is caused to remove transmission channel.Equalizer 406 is inessential assembly in this embodiment.The balanced signals of crossing of the last decoding of decoder 407, the signal S-that deciphered with output signal
OUT
According to one embodiment of the invention, signal analysis device 408 can comprise a correlation calculations device 411, symbol limit checkout gear 412, sequential mistake estimation unit 413 and carrier frequency drift estimation unit 414.The digital baseband signal S of correlation calculations device 411 in order to obtaining from fundamental frequency frequency mixer 404
BConjugate complex number and digital baseband signal S
BThe version that postpones of difference carry out behind the phase multiplication to obtain a plurality of operation results, again these a plurality of operation results and correlation calculations device 411 interior stored PN sequences are carried out respectively the computing of correlation (correlation), obtaining a plurality of correlativity calculation result, and produce correlation sequence C orr (n) according to a plurality of correlativity calculation result.Checkout gear 412 autocorrelation calculation elements 411 in symbol limit receive the correlation sequence, detect to have the maximum correlation sampling point in each frame, and note down correlation values and the position of this sampling point, to produce symbol limit index signal S-
INDSequential mistake estimation unit 413 is coupled to symbol limit checkout gear 412, in order to according to symbol limit index signal S-
INDThe information such as the position of the indicated sampling point with maximum correlation and correlation values (that is, the amplitude of this sampling point) produce back coupling control signal S
T, so that time sequence reply device 405 can be according to feedbacking control signal S
TWith digital baseband signal S
BResample, in order to return back to the sequential synchronous with the transmission end.Carrier frequency drift estimation unit 414 is coupled to symbol limit checkout gear 412 equally, in order to according to symbol limit index signal S-
INDThe correlation values of the indicated sampling point with maximum correlation (that is, the amplitude of this sampling point) is passed through suc as formula the drift of (1) described method estimating carrier frequency, and produces back coupling control signal S
C, so that fundamental frequency frequency mixer 404 can be according to feedbacking control signal S
CThe carrier frequency drift estimated value Δ f compensating carrier frequency offset that provides.
As mentioned above, because the signal that receives in the transmission channel environment of multi-path can produce the error items (as shown in Figure 2) with larger correlation when calculating correlation, thereby cause at the sampling point max (Corr that seeks maximum correlation
D(n)) obtain wrong result the time, the data information that makes the mistake is synchronous, and wrong carrier frequency drift estimated result (as shown in Figure 3).Therefore, according to one embodiment of the invention, correlation calculations device 411 is further strengthened required correlation when calculating correlation, so that required item can have maximum correlation values in the correlativity calculation result that obtains, so symbol limit checkout gear 412 can be found out required position exactly, and then sequential mistake estimation unit 413 and carrier frequency drift estimation unit 414 can correctly obtain the estimated value of timing synchronization information and carrier frequency drift.
Fig. 5 a-5c shows described in the correlativity calculation result of multi-path transmission channel environment according to one embodiment of the invention.Can know the concept of understanding required of the described reinforcement of one embodiment of the invention by Fig. 5 a-5c.After Fig. 5 a shows that the version according to the conjugate complex number of the DTMB data that receive and a delay D1 sampling point (as shown in Figure 1) of DTMB data carries out the phase multiplication, the resulting result of computing of the PN sequence execution correlation (correlation) that this operation result and receiver local side is stored again.As shown in the figure, suppose that sampling point n2 and n4 are required, the sampling point that mates the most of PN sequence in theory namely, being positioned at sampling point n1, n3 and n5 then is error items.Can be found out by Fig. 5 a, because the effect that the channel response of multi-path produces, so that it is quite approaching with required the correlation that is positioned at sampling point n2 to be positioned at the correlation of error items of sampling point n1, even greater than required the correlation that is positioned at sampling point n4, if be to find out very exactly required (in sampling point n2 and n4) to carry out timing synchronization and Frequency offset estimation according to the correlativity calculation result shown in Fig. 5 a therefore, thereby make a mistake.Fig. 5 b shows another correlation operation result, this result is after the version according to the conjugate complex number of the DTMB data that receive and a delay D2 sampling point (as shown in Figure 1) of DTMB data carries out the phase multiplication, the more resulting result of computing of the PN sequence execution correlation (correlation) that this operation result and receiver local side is stored.Can be found out by Fig. 5 b, because the effect that the channel response of multi-path produces, so that be positioned at required the correlation that the correlation of the error items of sampling point n5 is positioned at greatly sampling point n2, and greater than required the correlation that is positioned at sampling point n4, thereby can't tell required (in sampling point n2 and n4).If therefore carry out timing synchronization and Frequency offset estimation according to the correlativity calculation result shown in Fig. 5 b, then can make a mistake.
Yet, shown in Fig. 5 a and Fig. 5 b, the position that occurs owing to error items can change along with the length variations that postpones D, and required position that occurs can't change along with the difference that postpones D, therefore according to one embodiment of the invention, by the cumulative resulting correlativity calculation result of different delays of using, strengthen required correlation, so that can producing with error items in the correlativity calculation result that obtains, required item significantly separate, shown in Fig. 5 c, required item n2 after cumulative and the correlation of n4 and error items produce and significantly separate, thus, signal analysis device 408 can be exactly be found out required tram according to the correlativity calculation result of strengthening, and then obtains the accurately estimated value of timing synchronization and carrier frequency drift.
Fig. 6 shows according to the described correlation calculations device of one embodiment of the invention.According to one embodiment of the invention, correlation calculations device 611 can comprise two groups or more computing module.For clear elaboration concept of the present invention, Fig. 6 shows two groups of computing modules 612 and 613.It should be noted that the present invention also can use two groups of above computing modules; be not to be defined in to use two groups of computing modules; those skilled in the art can do some changes and retouching under the premise without departing from the spirit and scope of the present invention, so protection scope of the present invention is as the criterion with claim of the present invention.
According to embodiments of the invention, each computing module can comprise respectively two groups of first in first out (First In First Out is called for short FIFO) register.The length of first group of first-in first-out register designs according to different delay requirements respectively, and for example the length of first-in first-out register 621 can be designed to D1, in order to the digital baseband signal S with input
BPostpone D1 sampling point, and the length of first-in first-out register 631 can be designed to D2, in order to the digital baseband signal S with input
BPostpone D2 sampling point.Digital baseband signal S in process conjugate complex number unit (conjugator is referred to as conj) 622 and 632 with input
BAfter doing conjugate complex number (complex conjugate) conversion, digital baseband signal S
BConjugate complex number can multiply each other by multiplier 623 and 633 with the version of its delay D1 (or D2).Result after multiplying each other can further input to second group of first-in first-out register 624 and 634.Second group of first-in first- out register 624 and 634 lays respectively in correlation calculations unit 625 and 635, and in order to the computing of additional related, so its length can design with C2 according to required correlation length C 1 respectively.Digital baseband signal S
BConjugate complex number with postpone result after version multiplies each other and in correlation calculations unit 625 and 635, multiply each other with the stored PN sequence pointwise of receiver local side respectively by second group of first-in first- out register 624 and 634, and the multiplied result and then obtain correlativity calculation result Corr_D1 (n) and Corr_D2 (n) of adding up respectively.At last, by the adder 614 cumulative correlativity calculation result Corr_D1 (n) that obtain and Corr_D2 (n), in order to further to strengthen the correlation of required item, with output correlation sequence C orr (n).
Shown in Fig. 5 a-5c, the position that occurs owing to error items can change along with the length variations that postpones D, and required position that occurs can't change along with the difference that postpones D, through the cumulative resulting correlativity calculation result of different delays of using, can strengthen required correlation, so that required correlation can significantly separate with the error items generation in resulting correlation sequence.Therefore symbol limit checkout gear 421 sampling point with maximum correlation that can find exactly, and produce as mentioned above and feedback control signal S
CWith S-
TTo fundamental frequency frequency mixer 404 and time sequence reply device 405, to carry out carrier frequency drift estimation and time sequence reply.
Fig. 7 shows according to the described signal analysis method of one embodiment of the invention.At first, receive an input signal (step S701), wherein this input signal can be DTMB signal as shown in Figure 1a, comprise virtual noise sequence (PN Code) and data information (Data), and this input signal can be through the fundamental frequency signal after the 404 execution frequency reducing conversions of fundamental frequency frequency mixer.Then, postpone this input signal (step S702) according to a plurality of different retardations, for example, postpone this input signal according to two or more different retardations, to obtain respectively having the input signal of different retardations.Then, calculate described input signal with described different retardation and the correlation of a virtual noise sequence, to obtain a plurality of correlativity calculation result (step S703).Then, produce a correlation sequence (step S704) according to described correlativity calculation result.At last, according to original position and a carrier frequency drift amount (step S705) of this correlation sequencal estimation one data information.With reference to correlation calculations apparatus structure as shown in Figure 6, wherein step S702 can also comprise from step S703: conjugate complex number and the described input signal with different retardations of this input signal are multiplied each other, to obtain a plurality of multiplied result; And calculate this virtual noise sequence and correlation described multiplied result, and to obtain described correlativity calculation result, for example retardation D1 shown in Figure 6 and D2, and correlativity calculation result Corr_D1 (n) and Corr_D2 (n).In step S704, by cumulative Corr_D1 (n) and Corr_D2 (n) to produce correlation sequence C orr (n).
In addition, with reference to correlation calculations apparatus structure as shown in Figure 4, step S705 can also comprise: detect a sampling point that has maximum correlation among the correlation sequence C orr (n); A position and a correlation values according to this sampling point with maximum correlation produce symbol limit index signal S-
INDAnd original position and a carrier frequency drift amount of estimating this data information according to this symbol limit index signal.
Though the present invention discloses as above with preferred embodiment; so it is not to limit scope of the present invention; those skilled in the art can do some changes and retouching under the premise without departing from the spirit and scope of the present invention, so protection scope of the present invention is as the criterion with claim of the present invention.
Claims (11)
1. demodulation module comprises:
One analog-to-digital converter is changed an analog if signal, to export a digital medium-frequency signal;
One fundamental frequency frequency mixer, receive this digital medium-frequency signal, and to produce a fundamental frequency signal, wherein this fundamental frequency frequency mixer is also adjusted this carrier frequency according to one first back coupling control signal, to compensate the carrier frequency drift of this carrier frequency according to this digital medium-frequency signal of carrier frequency frequency reducing;
One sequential return mechanism is feedback control signal this fundamental frequency signal of resampling according to one second;
One signal analysis device, receive this fundamental frequency signal, analyze the correlation of this fundamental frequency signal and a predetermined virtual noise sequence to obtain a plurality of correlation results, and strengthen described correlation results producing a correlation sequence, and this first is feedback control signal and this second and feedbacks control signal according to this correlation sequence generation; And
One decoder, in order to deciphering an output signal of this time sequence reply device, producing a decoding output signal,
Wherein this signal analysis device comprises:
One correlation calculations device, receive this fundamental frequency signal, postpone this fundamental frequency signal to obtain inhibit signal according to a plurality of different retardations, and calculate described inhibit signal and be somebody's turn to do the correlation of being scheduled to the virtual noise sequence, obtaining described correlativity calculation result, and cumulative described correlativity calculation result is to obtain this correlation sequence;
One symbol limit checkout gear has a sampling point of maximum correlation according to this correlation Sequence Detection, and produces the marginal index signal of a symbol according to a position of this sampling point with a correlation values;
One carrier frequency drift estimation unit is estimated a carrier frequency drift amount according to this symbol limit index signal, and gives birth to this first back coupling control signal according to this carrier frequency drift volume production; And
One sequential mistake estimation unit produces this second back coupling control signal according to this symbol limit index signal.
2. demodulation module as claimed in claim 1 also comprises;
One equalizer, before this decoder is decoded this output signal of this time sequence reply device, this output signal of balanced this time sequence reply device, wherein an output signal of this this equalizer of decoder for decoding.
3. demodulation module as claimed in claim 1, wherein this carrier frequency drift estimation unit is estimated this carrier frequency drift amount according to this correlation values of this sampling point.
4. demodulation module as claimed in claim 1, wherein this sequential mistake estimation unit produces this according to this position of this sampling point and this correlation values and second feedbacks control signal.
5. demodulation module as claimed in claim 1, wherein this correlation calculations device comprises:
A plurality of computing modules, wherein each computing module comprises:
One first-in first-out register is in order to deposit this fundamental frequency signal of a set retardation;
One conjugation plurality of elements is in order to do this fundamental frequency signal the conjugate complex number conversion;
One multiplier is coupled to this first-in first-out register and this conjugate complex number unit, carries out multiplying in order to the output according to this first-in first-out register with an output of this conjugate complex number unit, to obtain a multiplied result; And
One correlation calculations unit is in order to calculate this multiplied result and the correlation that should be scheduled to the virtual noise sequence, to obtain this correlativity calculation result; And
One adder is in order to add up this correlativity calculation result of described correlation calculations unit output, to produce this correlation sequence.
6. signal analysis device in order to the estimating carrier frequency drift, comprising:
One correlation calculations device, receive an input signal, postpone this input signal to obtain a plurality of inhibit signals according to a plurality of different retardations, and calculate the correlation of described inhibit signal and a predetermined virtual noise sequence, obtaining a plurality of correlativity calculation result, and cumulative described correlativity calculation result is to produce a correlation sequence;
One symbol limit checkout gear has a sampling point of maximum correlation according to this correlation Sequence Detection, and produces symbol limit index signal according to a correlation values of this sampling point; And
One carrier frequency drift estimation unit is estimated a carrier frequency drift amount according to this symbol limit index signal.
7. signal analysis device as claimed in claim 6, this symbol limit checkout gear wherein, also the position according to this sampling point produces this symbol limit index signal, and described signal analysis device also comprises:
One sequential mistake estimation unit is estimated the original position of a data information of this input signal according to this symbol limit index signal.
8. signal analysis device as claimed in claim 6, wherein this correlation calculations device comprises:
A plurality of computing modules, wherein each computing module comprises:
One first-in first-out register is in order to deposit this input signal of a set retardation;
One conjugation plurality of elements is in order to do this input signal the conjugate complex number conversion;
One multiplier is coupled to this first-in first-out register and this conjugate complex number unit, carries out multiplying in order to the output according to this first-in first-out register with an output of this conjugate complex number unit, to obtain a multiplied result; And
One correlation calculations unit is in order to calculate this multiplied result and the correlation that should be scheduled to the virtual noise sequence, to obtain this correlativity calculation result; And
One adder is in order to add up this correlativity calculation result of described correlation calculations unit output, to produce this correlation sequence.
9. signal analysis method in order to the estimating carrier frequency drift, comprising:
Receive an input signal, wherein this input signal comprises a data information and a virtual noise sequence at least;
Postpone this input signal according to a plurality of different retardations, to obtain a plurality of inhibit signals;
Calculate the correlation of described inhibit signal and a predetermined virtual noise sequence, to obtain a plurality of correlativity calculation result;
Cumulative described correlativity calculation result is to produce a correlation sequence; And
According to a carrier frequency drift amount of this this input signal of correlation sequencal estimation,
Wherein the estimating step of this carrier frequency drift amount comprises:
A sampling point that has maximum correlation according to this correlation Sequence Detection; And
Estimate this carrier frequency drift amount according to a correlation values of this sampling point.
10. signal analysis method as claimed in claim 9 also comprises:
The original position of estimating this data information according to a position and this correlation values of this sampling point.
11. signal analysis method as claimed in claim 9, the calculation procedure of wherein said correlativity calculation result also comprises:
The one conjugation plural number of this input signal is multiplied each other with described inhibit signal, to obtain a plurality of multiplied result; And
Calculate the correlation of this predetermined virtual noise sequence and described multiplied result, to obtain described correlativity calculation result.
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| CN107105222B (en) * | 2016-02-23 | 2018-10-09 | 晨星半导体股份有限公司 | Symbol detection circuit and method |
| CN112242967B (en) * | 2020-09-11 | 2021-11-23 | 北京邮电大学 | Multi-carrier complementary code single code cyclic shift multiple access method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1411635A (en) * | 1999-10-19 | 2003-04-16 | 艾利森公司 | Apparatus and method for selection of correlation timing rake receivers |
| US20030117943A1 (en) * | 2001-12-26 | 2003-06-26 | Satoshi Sakata | Signal transmission system for transmitting a signal with a guard interval and a demodulation method thereof |
| CN101227443A (en) * | 2007-01-19 | 2008-07-23 | 华为技术有限公司 | Apparatus and method for generating training symbol and estimating bias of training symbol |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1411635A (en) * | 1999-10-19 | 2003-04-16 | 艾利森公司 | Apparatus and method for selection of correlation timing rake receivers |
| US20030117943A1 (en) * | 2001-12-26 | 2003-06-26 | Satoshi Sakata | Signal transmission system for transmitting a signal with a guard interval and a demodulation method thereof |
| CN101227443A (en) * | 2007-01-19 | 2008-07-23 | 华为技术有限公司 | Apparatus and method for generating training symbol and estimating bias of training symbol |
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