CN101114842B - Frame signal detection device for building dense city district - Google Patents
Frame signal detection device for building dense city district Download PDFInfo
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- CN101114842B CN101114842B CN200710042813A CN200710042813A CN101114842B CN 101114842 B CN101114842 B CN 101114842B CN 200710042813 A CN200710042813 A CN 200710042813A CN 200710042813 A CN200710042813 A CN 200710042813A CN 101114842 B CN101114842 B CN 101114842B
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Abstract
A frame-signal detection device which is suitable for a dense-constructed urban area is provided. Firstly, a frame head sequence correlator is used for correlating a currently received signal sequence with a pre-stored sequence to obtain a current correlated result; then, according to the current correlated result, a current signal path detection threshold value is generated, thus enabling a signal path screener to screen out a signal path from noises; furthermore, a signal path energy accumulator is used for accumulating the screened signal path energy, and at the same time, a frame detection threshold generator generates a current frame detection threshold value according to the current signal path detection threshold value. When the accumulated signal path energy exceeds the current frame detection threshold value, a signal maximum path is considered to be detected; lastly, the signal maximum path is searched out with a maximum path searcher, thus canceling out the effect of multi-paths and reducing the loss rate of frame signals.
Description
Technical field
The present invention relates to a kind of high speed image transmission system that is applicable to building dense city, relate in particular to frame signal checkout gear wherein.
Background technology
In existing communication system, application is all arranged in many instances based on the correlation detection technology of frame head sequence.See also Fig. 1, it is the exemplary block diagram of correlated series checkout gear.Described correlated series checkout gear comprises frame head sequence correlator, detection threshold maker, frame detector and maximum diameter searcher.In described frame signal checkout gear, frame head sequence correlator inside is provided with a local sequence memory, is used for the frame head sequence is stored in advance.During work, the frame head sequence of storing in current sequence that receives and the local sequence memory is sent into complex correlator simultaneously, be correlated with, and then added up by the correlated results of accumulator with each sampling point of frame head sequence, the result who adds up is exactly the relevant result of frame head sequence.The built-in threshold registers of described detection threshold maker, correlated results of the every output of frame head sequence correlator, the thresholding maker just is weighted summation with value in the threshold registers and correlated results, upgrades the value of threshold registers, and this result of calculation is just as new thresholding.Frame detector then compares the new threshold value of correlated results and the generation of detection threshold maker, when correlated results surpasses thresholding, then think to detect signal frame, enable the maximum diameter searcher of level behind the described frame detector at last, make it from correlated results, search for the maximum diameter of multipath signal.
Yet in the city of building dense, refraction is disturbed and is penetrated with scattering phenomenon more seriously, and the Channel Transmission multipath is serious.Because the influence of multipath, frame head sequence relevant peaks are dispersed on each footpath, do not have sharp-pointed relevant peaks in the correlated results of correlator output, so the correlated results gap of itself and noise path is not obvious, is difficult to surpass detection threshold, causes easily to lose and catches.Therefore, how to solve the shortcoming that has the existence of frame detection technique now and become the technical task that those skilled in the art need to be resolved hurrily in fact.
Summary of the invention
The object of the present invention is to provide a kind of frame signal checkout gear that is applicable to building dense city,, reduce the mistake of frame signal and catch rate to offset the influence of multipath.
In order to achieve the above object, the frame signal checkout gear of building dense city that is applicable to provided by the invention comprises: be used for carrying out relevant to obtain the frame head sequence correlator of current correlated results with the sequence of storage in advance the burst of current reception, be used for generating the signal footpath detection threshold maker of current demand signal footpath detection threshold value according to the current correlated results of threshold value that has generated and the acquisition of described frame head sequence correlator, be used for the correlated results of current described frame head sequence correlator acquisition and the current demand signal footpath detection threshold value of described signal footpath detection threshold maker generation are compared to filter out directly screening washer of current demand signal signal directly, the energy that is used for current demand signal footpath that described signal footpath screening washer is filtered out and the signal footpath energy that has added up are obtained the signal energy accumulation device directly of the gross energy of current multipath signal mutually, be used for generating the frame detection threshold maker of present frame detection threshold value according to the current demand signal footpath detection threshold value that described signal footpath detection threshold maker generates, be used for the frame detector whether present frame detection threshold value judgment frame signal that the gross energy that obtains according to described signal footpath energy accumulation device and described frame detection threshold maker generate has arrived, be used for when described frame detector is judged frame signal and arrived, going out the maximum diameter searcher of signal maximum diameter according to each related results search of described frame head sequence correlator.
Wherein, the current demand signal footpath detection threshold value that described signal footpath detection threshold maker generates is approximately the twice of each correlated results mean value in default time period, described signal footpath screening washer comprises first comparator and the selector of being controlled by described first comparator, described signal footpath energy accumulation device comprises the integrator that utilizes the time sliding window to constitute, adder that is connected with described integrator and the accumulator register that is connected with described adder, described maximum diameter searcher comprises the maximum diameter energy search unit of search signal maximum diameter, the signal maximum diameter that current correlated results that is used for the delay line that the current correlated results that described frame head sequence correlator obtains is delayed time and is used for described delay line is exported and described maximum diameter energy search unit have searched compares to judge whether that needs upgrade second comparator of described maximum diameter energy search unit data, wherein, the delay value coupling that delay value that described delay line adopts and described time sliding window adopt, described maximum diameter searcher also comprises the maximum diameter position search unit of upgrading described signal maximum diameter position according to the update signal of described second comparator.
In sum, the frame signal checkout gear of building dense city that is applicable to of the present invention screens from noise by the signal footpath with multipath signal, and add up, when the time sliding window of signal in the energy accumulation device just in time comprised all footpaths of multipath signal, the output of accumulator be exactly all signals footpath energy and, can offset the influence of multipath thus, recover the gross energy of signal, and then detect the signal ceiling capacity directly, reduce the mistake of frame signal and catch rate, can realize the synchronously thick of signal according to the signal maximum diameter position that searches simultaneously.
Description of drawings
Fig. 1 is the overall structure figure of existing frame signal checkout gear.
Fig. 2 is the overall structure figure that is applicable to the frame signal checkout gear of building dense city of the present invention.
Fig. 3 is signal footpath screening washer and the signal footpath energy accumulation device principle assumption diagram that is applicable to the frame signal checkout gear of building dense city of the present invention.
Fig. 4 is the maximum diameter searcher principle assumption diagram that is applicable to the frame signal checkout gear of building dense city of the present invention.
Embodiment
See also Fig. 2, the frame signal checkout gear of building dense city that is applicable to of the present invention comprises at least: frame head sequence correlator, signal footpath detection threshold maker, signal footpath screening washer, signal footpath energy accumulation device, frame detection threshold maker and frame detector maximum diameter searcher.
Described frame head sequence correlator is used for the burst of current reception and the sequence of storage are in advance carried out relevant to obtain current correlated results, and those skilled in the art know to its operation principle and structure, are not described in detail in this.
Described signal footpath detection threshold maker is used for generating current demand signal footpath detection threshold value according to the correlated results of threshold value that has generated and current described frame head sequence correlator acquisition, if the described threshold value that has generated is thresh, the current correlated results that obtains is cor, and the current demand signal that is then generated footpath detection threshold value thresh_new is:
Thresh_new=α * thresh+K* (1-α) * cor, wherein, α and K are constant, in the present embodiment, the value of α elects 63/64 as, can make approximate relevant with preceding 64 correlated results of current threshold value, guarantees the stationarity of threshold value; The value of K elects 2 as, can make current threshold value be approximately the twice of each correlated results mean value in default time period, promptly is approximately the twice of preceding 64 correlated results mean values, to guarantee to filter out most signal footpath.
Described signal footpath screening washer is used for the current demand signal footpath detection threshold value of the current correlated results of described frame head sequence correlator acquisition and the detection threshold maker generation of described signal footpath is compared to filter out the current demand signal footpath, see also Fig. 3, described signal footpath screening washer comprises first comparator and the selector of being controlled by described first comparator (MUX1), described current correlated results and signal footpath detection threshold value are sent in first comparator simultaneously, when current correlated results surpasses signal footpath detection threshold value, first comparator control selector is exported current correlated results, otherwise, selector output 0.As shown in Figure 3, current correlated results comprises P1 to P7 totally 7 peak values greater than signal footpath detection threshold value, and therefore, described selector is at 7 peak value place output correlated results, and all the other places are output as 0.
Described signal footpath energy accumulation device is used for the gross energy that current demand signal energy directly that described signal footpath screening washer is filtered out and the signal footpath energy that has added up are obtained current multipath signal mutually, it comprises and utilizes integrator that the time sliding window constitutes (as shown in Figure 3, described integrator is made of time sliding window and subtracter), adder that is connected with described integrator and the accumulator register that is connected with described adder, wherein, the integrating range of described integrator is elected effective multidiameter delay size of channel as, the length that just makes time window can guarantee the energy in all footpaths of multipath signal is all added up as far as possible near the length of channel delay like this.As shown in Figure 3, the signal footpath energy that filters out is sent into the described time sliding window and the part that adds up thereafter respectively, for certain specific moment, value in the accumulator register just equal all values in the time sliding window and, next constantly the value of accumulator register just deduct the value of throughput time sliding window simultaneously for the value of current time accumulator register adds the value of immigration time sliding window, promptly the value of accumulator storage remain all values in the time sliding window with.
Described frame detection threshold maker is used for generating the present frame detection threshold value according to the current demand signal footpath detection threshold value that described signal footpath detection threshold maker generates, in the present embodiment, the present frame detection threshold value that generates of described frame detection threshold maker is 8 times of the result that produces of signal footpath detection threshold maker.
Whether described frame detector is used for arriving according to the present frame detection threshold value judgment frame signal of the gross energy of described signal footpath energy accumulation device acquisition and the generation of described frame detection threshold maker, be that directly the gross energy and the present frame detection threshold of the output of energy accumulation device compare described frame detector with signal, when described gross energy surpasses detection threshold, think that then frame signal arrives, be that described frame detector sends frame signal arrival indication, see also Fig. 4.
Described maximum diameter searcher is used for that each related results search according to described frame head sequence correlator goes out the signal maximum diameter when described frame detector is judged frame signal and arrived, it comprises the maximum diameter energy search unit of search signal maximum diameter, be used for delay line with the current correlated results time-delay of described frame head sequence correlator acquisition, be used for the current correlated results of described delay line output is compared with second comparator that judges whether the described maximum diameter energy search unit data of needs renewal and the maximum diameter position search unit of upgrading described signal maximum diameter position according to the update signal of described second comparator with the signal maximum diameter that described maximum diameter energy search unit has searched, wherein, the delay value coupling that delay value that described delay line adopts and described time sliding window adopt, as shown in Figure 4, because needing signal footpath energy accumulation device to add up, frame detector just can detect frame after the energy in the most of footpath of multipath signal, at this moment, the signal maximum diameter occurs certainly, therefore in the maximum diameter searcher, need correlated results is carried out a time-delay, the time-delay size is elected effective multidiameter delay size of channel as, to guarantee that the value of maximum diameter is also in described delay line when frame detects index signal arrival.Described maximum diameter energy search unit comprises a maximum diameter energy register and a selector (MUX2), the initial value of maximum diameter energy register is 0, after the current output of delay line and maximum diameter energy register currency input to second comparator, when if the current output of delay line surpasses the currency of maximum diameter energy register, think and detect a bigger footpath, second comparator output control signal makes the current output of selector (MUX2) gating delay line, so selector ((MUX2) inputs to maximum diameter energy register with the current output of delay line and upgrades; And when if the current output of delay line surpasses the currency of maximum diameter energy register, maximum diameter energy register continues to keep currency.Described maximum diameter position search unit is made up of a deviation post counter, maximum diameter location register and a selector (MUX3).Offset counter is the counter that a frame signal by frame detector output arrives indication control, counter begins counting after frame detector detects frame signal, and makes the sampling sequence number of the relative frame detection signal of value indication current delay line output valve of its counting.When the current output of delay line surpassed the currency of maximum diameter energy register, the control signal of second comparator output made the result of selector (MUX3) gating deviation post counter upgrade the maximum diameter location register.When the current output of delay line did not surpass the currency of maximum diameter energy register, the maximum diameter location register kept currency.In addition, after frame signal that described frame detector sends arrives indication and inputs to described second comparator and described deviation post counter, can make no longer operate as normal of described second comparator and described deviation post counter.
In sum, the frame signal checkout gear of building dense city that is applicable to of the present invention screens from all results by the signal footpath with multipath signal, and add up, when the time sliding window in the energy accumulation device of signal footpath has just in time comprised all footpaths of multipath signal, the output of signal footpath energy accumulation device be exactly all signals footpath energy and, thereby eliminate the influence of multipath to the signal correction peak, probability is caught in the mistake that is reduced in the multipath serious environmental, can realize the synchronously thick of signal according to the position of the signal maximum diameter that obtains simultaneously.
Claims (5)
1. frame signal checkout gear that is applicable to building dense city is characterized in that comprising:
The frame head sequence correlator is used for carrying out relevant to obtain current correlated results with the sequence of storage in advance the burst of current reception;
Signal footpath detection threshold maker, be used for generating current demand signal footpath detection threshold value according to the current correlated results of threshold value that has generated and the acquisition of described frame head sequence correlator, wherein, the current demand signal that generated footpath detection threshold value is approximately the twice of each correlated results mean value in default time period;
Signal footpath screening washer is used for the correlated results of current described frame head sequence correlator acquisition and the current demand signal footpath detection threshold value of described signal footpath detection threshold maker generation are compared to filter out the current demand signal footpath;
Signal footpath energy accumulation device is used for the gross energy that current demand signal energy directly that described signal footpath screening washer is filtered out and the signal footpath energy that has added up are obtained current multipath signal mutually;
Frame detection threshold maker, be used for generating the present frame detection threshold value according to the current demand signal footpath detection threshold value that described signal footpath detection threshold maker generates, wherein, the present frame detection threshold value that is generated is 8 times of the result that produces of described signal footpath detection threshold maker;
Whether frame detector is used for arriving according to the gross energy of described signal footpath energy accumulation device acquisition and the present frame detection threshold value judgment frame signal of described frame detection threshold maker generation;
The maximum diameter searcher is used for that each related results search according to described frame head sequence correlator goes out the signal maximum diameter when described frame detector is judged frame signal and arrived.
2. the frame signal checkout gear that is applicable to building dense city as claimed in claim 1 is characterized in that: described signal footpath screening washer comprises first comparator and the selector of being controlled by described first comparator.
3. the frame signal checkout gear that is applicable to building dense city as claimed in claim 1 is characterized in that: described signal footpath energy accumulation device comprises the integrator that utilizes the time sliding window to constitute, the adder that is connected with described integrator and the accumulator register that is connected with described adder.
4. the frame signal checkout gear that is applicable to building dense city as claimed in claim 3, it is characterized in that: described maximum diameter searcher comprises the maximum diameter energy search unit of search signal maximum diameter, the signal maximum diameter that current correlated results that is used for the delay line that the current correlated results that described frame head sequence correlator obtains is delayed time and is used for described delay line is exported and described maximum diameter energy search unit have searched compares to judge whether that needs upgrade second comparator of described maximum diameter energy search unit data, wherein, the delay value coupling of the delay value of described delay line employing and described time sliding window employing.
5. the frame signal checkout gear that is applicable to building dense city as claimed in claim 4 is characterized in that described maximum diameter searcher also comprises: the maximum diameter position search unit of upgrading described signal maximum diameter position according to the update signal of described second comparator.
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| CN101286794B (en) * | 2008-03-05 | 2012-11-07 | 中国科学院嘉兴无线传感网工程中心 | Frame synchronizing device applied in wireless sensor network |
| CN102957506B (en) * | 2011-08-31 | 2015-08-19 | 北京中电华大电子设计有限责任公司 | A kind of 802.11 noise signals open preamble detecting processing method and device by mistake |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1265490A (en) * | 1999-03-02 | 2000-09-06 | 日本电气株式会社 | CDMA receiver |
| EP1306986A2 (en) * | 2001-10-25 | 2003-05-02 | Electronics and Telecommunications Research Institute | Cell search system for mobile station in a time division duplex system and method for the same |
| CN1529525A (en) * | 2003-10-09 | 2004-09-15 | 北京天�科技有限公司 | Device and method for detecting defined frame synchronization of channel contour window |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1265490A (en) * | 1999-03-02 | 2000-09-06 | 日本电气株式会社 | CDMA receiver |
| EP1306986A2 (en) * | 2001-10-25 | 2003-05-02 | Electronics and Telecommunications Research Institute | Cell search system for mobile station in a time division duplex system and method for the same |
| CN1529525A (en) * | 2003-10-09 | 2004-09-15 | 北京天�科技有限公司 | Device and method for detecting defined frame synchronization of channel contour window |
Non-Patent Citations (2)
| Title |
|---|
| 高音 等.802.11a WLAN系统的帧同步检测方法.计算机工程31 19.2005,31(19),第120～122页. |
| 高音 等.802.11a WLAN系统的帧同步检测方法.计算机工程31 19.2005,31(19),第120～122页. * |
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