CN101989969B - PN sequence phase detection method and device - Google Patents
PN sequence phase detection method and device Download PDFInfo
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- CN101989969B CN101989969B CN 200910057711 CN200910057711A CN101989969B CN 101989969 B CN101989969 B CN 101989969B CN 200910057711 CN200910057711 CN 200910057711 CN 200910057711 A CN200910057711 A CN 200910057711A CN 101989969 B CN101989969 B CN 101989969B
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Abstract
The invention discloses a PN sequence initial phase detection method comprising the following steps: causing a received signal to relate to a local PN sequence so as to obtain a series of relative values; removing the relative values generated by the fact that a PN sequence length exceeds one period from a series of relative values, and calling the relative values as parasitic peaks; obtaining a plurality of relative values from the relative values of which the parasitic peaks are removed according to the same rule, solving the difference between the distance between two adjacent relative values and the length between PN sequences of a transmitting terminal, and calling the difference as a peak distance difference for short; selecting one peak distance difference with high reliability from a plurality of adjacent peak distance differences for calculating detection phase; and judging whether the detection phase is reliable according to phase verification. The invention also discloses a PN sequence phase detection device. The method and the device of the invention can improve the accuracy, the reliability and the detection speed of the detection phase under the condition that clock errors exist, the phase verification is used to judge whether the detection phase is reliable, and the correct probability of detection is improved under multipath channel.
Description
Technical field
The present invention relates to digital processing field, particularly relate to a kind of PN sequence phase detection method for the digital signal reception.The invention still further relates to the device of this method of realization.
Background technology
China Digital TV terrestrial broadcasting standard GB 20600-2006 " digital television ground broadcast transmission system frame structure, chnnel coding and modulation " specified signal frame is made up of frame head, frame.Frame head mode has three kinds, and wherein the initial phase of the LFSR (Liner Feedback ShiftRegister, linear feedback shift register) of pattern 1, mode 3 generation PN sequence changes and do not change two kinds of patterns.A plurality of signal frames are formed 1 superframe, and when the sequence number of system requirements index signal frame, the frame head of the signal frame in each superframe adopts the PN sequence of out of phase as identifier.
Since receiver need utilize the PN sequence carry out frame synchronization, Frequency Synchronization, regularly synchronously, channel impulse response estimation, tracking phase noise, so whether the receiver of national standard digital tv ground broadcasting need detect the phase place and the phase place that receive the PN sequence and rotate.
Chinese invention patent ublic specification of application CN1677909A (open day: on October 5th, 2005) disclose a kind of " frame synchornization method of time-domain synchronization OFDM receiver and system thereof ", related to the method for phase calculation, but it is the anti-change of the phase change rule of China Digital TV terrestrial broadcasting standard GB20600-2006 regulation, directly use can cause in multipath channel and exist under the situation of clocking error, and the phase-detection error probability is very high.
Summary of the invention
Technical problem to be solved by this invention provides a kind of PN sequence initial phase detection method, can improve correctness, reliability and the detection speed of PN phase-detection; The present invention also provides a kind of PN sequence initial phase checkout gear for this reason.
For solving the problems of the technologies described above, PN sequence initial phase detection method of the present invention is to adopt following technical scheme to realize:
It is relevant with local PN sequence to receive signal, obtains a series of correlations; From described a series of correlations, remove the parastic wasp that the PN sequence length produces above one-period; Obtain a plurality of correlations according to same rule the correlation after removing parastic wasp, and obtain distance between adjacent two correlations and the difference of the length between the transmitting terminal PN sequence, it is poor that this difference is called peak distance; From continuous a plurality of peak distance differences, select with a high credibility being used for to calculate detected phase; Carry out the phase bit check, judge whether detected phase is credible.
PN sequence initial phase checkout gear of the present invention comprises:
Computing unit, it is relevant with local PN sequence to be used for receiving signal, obtains a series of correlations;
Remove the parastic wasp unit, be connected with computing unit, remove the parastic wasp that the PN sequence length produces above one-period;
Acquiring unit is connected with removal parastic wasp unit, and it is poor to select a plurality of correlations and obtain peak distance for the correlation after removal parastic wasp, and it is poor to select one of them peak distance that meets rule from continuous a plurality of peak distance differences;
Phase calculation unit is connected with acquiring unit, utilizes the relation between peak distance difference and the phase place to draw detected phase;
The phase place verification unit is connected with phase calculation unit, is used for judging whether detected phase is credible, if detected phase is insincere, then obtains the peak distance difference again and calculates detected phase.
The present invention improves correctness, reliability and detection speed with the detected phase under the clocking error by select the phase calculation of carrying out with a high credibility from a plurality of peak distance differences; Judge by the phase bit check whether detected phase is credible, improve the detection correct probability under multipath channel.
Description of drawings
The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments:
Fig. 1 is PN sequence phase detection method flow chart;
Fig. 2 is PN sequence phase checkout gear structural representation;
Fig. 3 is frame head mode 1,3 structural representations;
Fig. 4 is PN sequence correlation peak schematic diagram;
Fig. 5 is that clocking error disturbs schematic diagram;
Fig. 6 is that strong multipath disturbs schematic diagram.
Embodiment
Referring to shown in Figure 1, PN sequence phase detection method of the present invention may further comprise the steps:
The first step is carried out related operation with local PN sequence and reception signal, obtains a series of correlations.Receiving signal can sample according to character rate, also can over-sampling, and for convenience of description, the present invention describes with character rate.The initial phase of local PN sequence can change also and can not change.
In second step, if the PN sequence length of transmitting terminal surpasses one-period, then need to eliminate the correlation that the expansion part causes.The length of the PN sequence in receiving signal surpasses one-period, do not having under the channel of multipath, with the local PN sequence relevant a plurality of bigger correlations that still can produce that slide, here a correlation with maximum is called relevant peaks, and all the other are called parastic wasp by the correlation that the PN sequence length produces above one-period.Phase place method of calibration according to different might need to remove parastic wasp.
Remove parastic wasp: in above-mentioned a series of correlations, remove less correlation (namely remove and disturb), and in remaining correlation, take a decision as to whether parastic wasp one by one.If occur peak value with current peak value on the position of a PN sequence period, then current peak value is not parastic wasp yet, otherwise is the parastic wasp that needs removal.
Fig. 3 is frame head mode 1,3 structural representations; Wherein, Fig. 3 (a) is frame head mode 1 structural representation; Fig. 3 (b) is frame head mode 3 structural representations.Less peak value shown in Fig. 4 is exactly parastic wasp.
In the 3rd step, select peak distance with a high credibility poor.
Obtain a plurality of correlations according to same rule the correlation after removing parastic wasp, and obtain distance between adjacent two correlations and the difference of the length between the transmitting terminal PN sequence, it is poor that this difference is called peak distance.Described same rule refers to amplitude rule, position rule or uses amplitude rule and position rule to make up the rule of definition.From continuous a plurality of peak distance differences, select peak distance with a high credibility poor.
Because the clock of receiver has error with the clock of transmitter, is called clocking error, therefore the difference DELTA d of the distance of the peak value of adjacent two frames and frame length since the influence of clocking error become: Δ d+ τ, τ are the errors of clocking error introducing, as shown in Figure 5.Owing to introduced clocking error, the peak distance difference that therefore needs to comprise clocking error is got rid of, and the peak distance difference of selecting not comprise clocking error is calculated phase place.For example: in GB 20600-2006, can pass through continuous a plurality of peak distance differences are used for the judgement of increasing or decreasing, and it is poor as believable peak distance therefrom to select one of them the peak distance difference that meets the negative even number of positive odd number or negative odd number positive even numbers rule.Select the method for believable peak distance difference to also have: when the Changing Pattern that a plurality of peak distance differences all meet among the GB 20600-2006 is just selected, but when clocking error was relatively large, detected phase institute's time spent was longer, or is difficult to detect phase place.
Be that (referring to Fig. 3 a), it is that 0 PN sequence is relevant that the variation of PN sequence phase reaches with phase place in proper order to example, and the peak distance difference of adjacent two frames is as shown in table 1 below with the frame head mode 1 of China Digital TV terrestrial broadcasting standard GB 20600-2006 defined.
Adjacent two peak distance difference are not expressed as: Δ d
i, Δ d
I+1, ideally || Δ d
I+1|-| Δ d
i||=1, but have clocking error in the reality, therefore || Δ d
I+1|-| Δ d
i||=1+ τ, τ are the error that clocking error is introduced, wherein Δ d
iThe difference of distance and frame length of representing the peak value of i frame and i-1 frame.Because introduced clocking error, adjacent | Δ d| might equate.Therefore for anti-clocking error, use n adjacent peak distance difference to make comparisons mutually.As long as guarantee | Δ d
I+n|＞| Δ d
i| and | Δ d
I+n| 〉=| Δ d
I+n-1| 〉=... 〉=| Δ d
i|; Or | Δ d
I+n|＜| Δ d
i|, and | Δ d
i| 〉=... 〉=| Δ d
I+n-1| 〉=| Δ d
I+n|, just can estimate the variation relation (increasing or decreasing) of peak distance difference.
Under the ideal conditions, | Δ d
i| with | Δ d
I+n| difference should be n, consider the influence of clocking error, difference may be n+n τ.Therefore work as and judge that the peak distance difference increases progressively, and | Δ d
I+n|-| Δ d
i| during＜n+n τ, think to exist in this adjacent n peak distance difference to meet the Δ d that calculates the PN sequence phase; Successively decrease if judge the peak distance difference, and | Δ d
i|-| Δ d
I+n| during＜n+n τ, think to exist in this adjacent n peak distance difference to meet the Δ d that calculates the PN sequence phase.Increase progressively if judge the peak distance difference, then select the Δ d of negative odd number or positive even numbers; Successively decrease if judge the peak distance difference, then select the Δ d of positive odd number or negative even number.
Table 1
| PN sequence phase sequence number | Δd | PN sequence phase sequence number | Δd |
| 0 | 0 | 113 | -112 |
| 1 | -1 | 114 | 111 |
| 2 | 2 | 115 | -110 |
| 3 | -3 | 116 | 109 |
| 4 | 4 | 117 | -108 |
| ...... | ...... | ...... | ...... |
| 109 | -109 | 221 | -4 |
| 110 | 110 | 222 | 3 |
| 111 | -111 | 223 | -2 |
| 112 | 112 | 224 | 1 |
The 4th step, calculate detected phase, the peak distance difference of adjacent two signal frames is unique, and with initial phase corresponding (referring to table 1) one by one, utilize the relation between peak distance difference and the phase place to calculate detected phase.For the frame head mode 1 of China Digital TV terrestrial broadcasting standard GB 20600-2006, when the peak distance difference increases progressively, detected phase phase=| Δ d|; When the peak distance difference is successively decreased, detected phase phase=phase_num-| Δ d|, phase_num represents the sum of initial phase.
The 5th step, the phase bit check.Whether the verification detected phase is calculated correctly.As shown in Figure 6, if use the strongest relevant peaks to carry out phase-detection, when the relevant peaks that exists a plurality of intensity to equate, owing to be subjected to The noise, might cause the relevant peaks of selecting to participate in the phase bit check inconsistent, thereby cause the detection mistake.In addition, select to participate in the relevant peaks of phase bit check in any mode, all similar situation might occur, for fear of detecting mistake, need carry out the phase bit check.
Carry out the combination in any of phase bit check following any one method of employing or following method,
Method one is used double or twice above mutual verification of detected phase result of calculation.
Method two, according to detected phase result of calculation, if follow-up peak distance difference be zero by verification.
Method three, it is poor to use different criterions to select correlation also to draw peak distance respectively, calculates detected phase respectively, by relatively whether two detected phase are identical, judges whether this detected phase is reliable.For example calculate detected phase with the same relevant peaks in each PN sequence period, utilize this detected phase to obtain the phase place of later PN sequence afterwards, the relevant peak-to-peak number of samples of each frame is consistent with signal frame length so by check later on, and this detected phase is correct.
Referring to shown in Figure 2, PN sequence phase checkout gear comprises in one embodiment of this invention:
Computing unit carries out related operation with local PN sequence and reception signal, obtains a series of correlations.
Remove the parastic wasp unit, be connected with computing unit, remove the parastic wasp of being correlated with and producing when the PN sequence length surpasses one-period.If occur peak value with current peak value on the position of a PN sequence period, then current peak value is not parastic wasp yet, otherwise is the parastic wasp that needs removal.
Acquiring unit is connected with removal parastic wasp unit, select a plurality of correlations for the correlation after removal parastic wasp, and it is poor to obtain peak distance, and it is poor to be used for selecting one of them peak distance that meets rule from continuous a plurality of peak distance differences.Continuous a plurality of peak distance difference is for the judgement that increases progressively, successively decreases, and it is poor as believable peak distance therefrom to select one of them the peak distance difference that meets the negative even number of positive odd number or negative odd number positive even numbers rule.
Phase calculation unit is connected with acquiring unit, utilizes the relation between peak distance difference and the phase place to calculate detected phase.Frame head mode 1 with China Digital TV terrestrial broadcasting standard GB 20600-2006 is example, when the peak distance difference increases progressively, and detected phase phase=| Δ d|; When the peak distance difference is successively decreased, detected phase phase=phase_num-| Δ d|.
The phase place verification unit is connected with phase calculation unit, is used for judging whether detected phase is credible, if detected phase is insincere, then obtains the peak distance difference again and calculates phase place.Need the detected phase place of storage, and detected phase place is added up frame by frame, up to calculating all detected phase, relatively whether two phase places are identical afterwards, thereby judge whether this phase place is reliable.
More than by specific embodiment the present invention is had been described in detail, but these are not to be construed as limiting the invention.Under the situation that does not break away from the principle of the invention, those skilled in the art also can make many distortion and improvement, and these also should be considered as protection scope of the present invention.
Claims (5)
1. PN sequence initial phase detection method, it is characterized in that: it is relevant with local PN sequence to receive signal, obtains a series of correlations; From described a series of correlations, remove the parastic wasp that the PN sequence length produces above one-period; Described parastic wasp refers to because the PN sequence length surpasses one-period, relevant the obtaining of sliding, the relevant peaks except maximum correlation peak; Obtain a plurality of correlations according to same rule the correlation after removing parastic wasp, described same rule refers to amplitude rule, position rule or uses amplitude rule and position rule to make up the rule of definition; And obtain distance between adjacent two correlations and the difference of the length between the transmitting terminal PN sequence, it is poor that this difference is called peak distance; From continuous a plurality of peak distance differences, select with a high credibility being used for to calculate detected phase; Carry out the phase bit check, judge whether detected phase is credible.
2. the method for claim 1, it is characterized in that: the method for the peak distance difference that described selection is with a high credibility is, continuous a plurality of peak distance differences are judged by increasing or decreasing it is poor as peak distance with a high credibility therefrom to select one of them the peak distance difference that meets the negative even number of positive odd number or negative odd number positive even numbers rule.
3. the method for claim 1, it is characterized in that: the method for described phase bit check is to adopt the combination in any of following any one method or following method:
Method one is used twice or twice above mutual verification of detected phase result of calculation;
Method two, according to detected phase result of calculation, if follow-up peak distance difference be zero by verification;
Method three uses different criterions to select correlation, utilizes different correlation value calculation detected phase, by relatively whether two detected phase are identical, judges whether this detected phase is reliable.
4. a PN sequence initial phase checkout gear is characterized in that, comprising:
Computing unit, it is relevant with local PN sequence to be used for receiving signal, obtains a series of correlations;
Remove the parastic wasp unit, be connected with computing unit, remove the parastic wasp that the PN sequence length produces above one-period; If occur peak value with current peak value on the position of a PN sequence period, then current peak value is not parastic wasp, otherwise is the parastic wasp that will remove yet;
Acquiring unit is connected with removal parastic wasp unit, and it is poor to select a plurality of correlations and obtain peak distance for the relevant peaks after removal parastic wasp, and it is poor to select one of them peak distance that meets rule from continuous a plurality of peak distance differences; When selecting relevant peaks, obtain a plurality of correlations according to same rule, described same rule refers to amplitude rule, position rule or uses amplitude rule and position rule to make up the rule of definition;
Phase calculation unit is connected with acquiring unit, utilizes the relation between peak distance difference and the phase place to draw detected phase;
The phase place verification unit is connected with phase calculation unit, is used for judging whether detected phase is credible, if detected phase is insincere, then obtains the peak distance difference again and calculates detected phase.
5. device as claimed in claim 4 is characterized in that, described phase place verification unit comprises:
Memory cell is used for the storage detected phase;
The unit that adds up is used for when next PN sequence arrives, and operation adds up on the basis of the detected phase that has drawn;
Comparing unit is used for relatively whether two detected phase are identical.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5737361A (en) * | 1994-11-22 | 1998-04-07 | Samsung Electronics Co., Ltd. | Receiver in a direct-sequence spread-spectrum communication system using a window filter |
| CN1677909A (en) * | 2004-03-31 | 2005-10-05 | 清华大学 | Frame synchronizing method for time-domain synchronous orthogonal frequency-division duplex receiver and system |
| CN101304403A (en) * | 2008-06-30 | 2008-11-12 | 北京海尔集成电路设计有限公司 | Method and system for frame synchronization |
-
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5737361A (en) * | 1994-11-22 | 1998-04-07 | Samsung Electronics Co., Ltd. | Receiver in a direct-sequence spread-spectrum communication system using a window filter |
| CN1677909A (en) * | 2004-03-31 | 2005-10-05 | 清华大学 | Frame synchronizing method for time-domain synchronous orthogonal frequency-division duplex receiver and system |
| CN101304403A (en) * | 2008-06-30 | 2008-11-12 | 北京海尔集成电路设计有限公司 | Method and system for frame synchronization |
Non-Patent Citations (3)
| Title |
|---|
| 中华人民共和国国家质量监督检验检疫总局等.数字电视地面广播传输系统帧结构、信道编码和调制.《中华人民共和国国家标准GB 20600-2006》.2006,全文. * |
| 直序扩频信号PN码相位的自适应测量算法;龚国辉等;《电子学报》;20060731;第34卷(第7期);第1325-1328页 * |
| 龚国辉等.直序扩频信号PN码相位的自适应测量算法.《电子学报》.2006,第34卷(第7期),第1325-1328页. |
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