CN104219191A - Orthogonal carrier frequency division multiplexing signal processing method and specific pilot frequency domain signal estimation method - Google Patents
Orthogonal carrier frequency division multiplexing signal processing method and specific pilot frequency domain signal estimation method Download PDFInfo
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Abstract
The invention relates to an orthogonal carrier frequency division multiplexing signal processing method and a specific pilot frequency domain signal estimation method. The orthogonal carrier frequency division multiplexing signal processing method includes that a second signal is updated to a received orthogonal carrier frequency division multiplexing signal on a frequency domain, and a first signal is updated to the original second signal; channel estimation is performed according to the first signal and the second signal; an inter-symbol interference result is estimated; the second signal or the first signal is updated according to the inter-symbol interference result; a first interchannel interference result is estimated; a second interchannel interference result is estimated by the first interchannel interference result; the second signal or the first signal is updated according to the second interchannel interference result; the first signal is subjected to equilibrium processing, and the first signal after the equilibrium processing is output. Besides, by means of a specific pilot frequency domain signal estimation method and device, a specific pilot frequency domain signal can be estimated and used for the orthogonal carrier frequency division multiplexing signal processing method.
Description
Technical field
The present invention relates to a kind of digital television broadcasting (Digital Video Broadcasting, DVB) system, and the particularly a kind of processing method of quadrature carrier frequency division multiplexed signals (Orthogonal Frequency Division Multiplexing, OFDM) of the receiver for digital television broadcasting system and estimating and measuring method, the device of special pilot frequency-region signal.
Background technology
Quadrature carrier frequency division multiplexed signals is a kind of multicarrier modulated signal, and it can resist multi-path delay spread (multi-path delay spreading) effectively, thus adopt by digital TV broadcast standards.In digital TV broadcast standards; in order to avoid code border interference (Inter-Symbol Interference, ISI), its design is between two adjacent quadrature carrier frequency division multiplexed signalss; insert protection interval (Guard Interval, GI).In general, if the length at protection interval can be greater than the maximum delay expansion of radio channel, then the multipath component of the quadrature carrier frequency division multiplexed signals received at present can be avoided can not to cause interference to the quadrature carrier frequency division multiplexed signals that the next one receives.But the length at protection interval is longer, then bandwidth efficiency (channel efficiency) is lower.Therefore, generally can select the protection interval that length is minimum, promote bandwidth efficiency, and by the mode of signal transacting, increase the ability of opposing code border interference.
In the receiver of current digital television broadcasting system; someone is set forth in time domain (time domain) and arranges adaptability (adaptive) filter to not carrying out fast fourier transform (Fast Fourier Transform; the quadrature carrier frequency division multiplexed signals of reception FFT) carries out filtering process; too weak with the ability of the protection interval avoiding length shorter opposing code border interference, also i.e. blanking code border interference.But, because pilot tone (pilot frequency) signal is in the upper insertion of frequency domain (frequency domain), therefore in time domain, adjust the coefficient of self-scalability filter and be not easy, resulting in practice time domain being arranged adaptability filter and can produce larger cost price.
In addition on the one hand, someone proposes to take out multiple pilot tone frequency-region signal to the quadrature carrier frequency division multiplexed signals of the reception after carrying out fast fourier transform, after again inverse fast fourier transform and fast fourier transform being carried out to multiple pilot tone frequency-region signal, carry out channel estimation, to obtain channel estimation result.Then, then compensate the quadrature carrier frequency division multiplexed signals after demodulation according to channel estimation result, with blanking code border interference by this.But this kind of practice needs to carry out fast fourier transform and inverse fast fourier transform in multiple times, therefore cost is higher.
Moreover, in employing second generation ground digital television broadcast (Digital Video Broadcasting – Second Generation Terrestrial, DVB-T2) digital television broadcasting system of standard, if receiver will process quadrature carrier frequency division multiplexing signal on frequency domain, with the interference of blanking code border and interchannel interference, then inevitably needing estimation P1 pilot tone frequency-region signal in some cases.But, only there is definition how to produce P1 pilot tone time-domain signal before second generation ground digital television broadcast standard mesh, and do not inform how to estimate P1 pilot tone frequency-region signal.
Summary of the invention
The embodiment of the present invention provides a kind of processing method of quadrature carrier frequency division multiplexed signals, and it disturbs and interchannel interference with for blanking code border, and the step general description of the processing method of quadrature carrier frequency division multiplexed signals is as follows.Temporary first signal and secondary signal respectively.Receive the quadrature carrier frequency division multiplexed signals on frequency domain, described secondary signal being updated to the quadrature carrier frequency division multiplexed signals on described frequency domain, is former secondary signal by described first signal update.Carry out channel estimating according to described first signal and described secondary signal, and produce channel estimation result.When particular frame activation signal or special pilot activation signal are non-real, based on described first signal or described secondary signal, and based on described channel estimation result, estimation code border interference result.When particular frame activation signal and special pilot activation signal are very, estimate described code border based on special pilot frequency-region signal and described channel estimating result and disturb result.Described secondary signal or the first signal is upgraded according to described code border interference result.Based on described secondary signal or the first signal, and disturb result based between described channel estimation result estimation first passage.Based on described secondary signal or the first signal, and based on disturbing result and described channel estimation result between described first passage, between estimation second channel, disturb result.Described secondary signal or the first signal is upgraded according to disturbing result between described second channel.Equilibrium (equalization) process is carried out to described first signal, and exports described first signal after equilibrium treatment.
The embodiment of the present invention also provides a kind of estimating and measuring method of special pilot frequency-region signal, and it described special pilot frequency-region signal for estimating, and the step of the estimating and measuring method of described special pilot frequency-region signal is described as follows.First, special pilot time-domain signal is obtained.Then, fast fourier transform is carried out to special pilot time-domain signal, to obtain First ray signal.Afterwards, First ray signal is carried out to first and second frequency reducing sampling process of 0.5 frequency multiplication, obtain first and second frequency reducing sampling sequence signal respectively to obtain, wherein first and second frequency reducing sampling process system obtains multiple odd point of First ray signal and multiple signal values of even number point respectively.Then, first-phase displacement process, the first low-pass filtering treatment and second-phase displacement process are sequentially carried out to first and second frequency reducing sampling sequence signal, to produce second and the 3rd sequence signal respectively.In addition, zero padding interpolation processing is carried out to First ray signal, to produce the 4th sequence signal.Then, first to fourth sequence signal is chosen as the 5th sequence signal according to echo mode signal and fast fourier transform mode signal.Afterwards, carry out after third phase displacement process, the second low-pass filtering treatment, the 4th phase shift process to be multiplied with norm and to process, described special pilot frequency-region signal to estimate to the 5th sequence signal in order.
The embodiment of the present invention also provides a kind of estimating apparatus of special pilot frequency-region signal, described special pilot frequency-region signal for estimating, and the estimating apparatus of described special pilot frequency-region signal comprises fast fourier transformer, sequence signal processor and special pilot frequency-region signal generator, sequence signal processor described in wherein said fast fourier transformer electric property coupling, and special pilot frequency-region signal generator described in described sequence signal processor electric property coupling.Described fast fourier transformer obtains special pilot time-domain signal, and carries out fast fourier transform to special pilot time-domain signal, to obtain First ray signal.Described sequence signal processor carries out first and second frequency reducing sampling process of 0.5 frequency multiplication to First ray signal, obtain first and second frequency reducing sampling sequence signal respectively to obtain, wherein first and second frequency reducing sampling process system obtains multiple odd point of First ray signal and multiple signal values of even number point respectively.Then, described sequence signal processor sequentially carries out first-phase displacement process, the first low-pass filtering treatment and second-phase displacement process to first and second frequency reducing sampling sequence signal, to produce second and the 3rd sequence signal respectively.In addition, described sequence signal processor carries out zero padding interpolation processing to First ray signal, to produce the 4th sequence signal.Then, described sequence signal processor chooses first to fourth sequence signal as the 5th sequence signal according to echo mode signal and fast fourier transform mode signal.Afterwards, described special pilot frequency-region signal generator carries out after third phase displacement process, the second low-pass filtering treatment, the 4th phase shift process to be multiplied with norm and to process, described special pilot frequency-region signal to estimate to the 5th sequence signal in order.
Comprehensive the above, embodiments provide a kind of processing method of quadrature carrier frequency division multiplexed signals, it use that interative computation, reliable decision region and pilot aided are adjudicated, process on simple frequency domain, use the means such as two signal estimated channel to come blanking code border to disturb and interchannel interference.In addition, the embodiment of the present invention additionally provides a kind of estimating and measuring method, device of special pilot frequency-region signal, and it can be estimated and described special pilot frequency-region signal, and the processing method for described quadrature carrier frequency division multiplexed signals uses.
For enable feature and the technology contents of further understanding the present invention, refer to the following detailed description about the present invention and accompanying drawing, but these illustrate that with institute's accompanying drawings be only for the present invention is described, but not any restriction is done to claim of the present invention.
Accompanying drawing explanation
Fig. 1 is the block diagram of the receiver of the embodiment of the present invention.
Fig. 2 is the block diagram of the balanced decision-making device of the embodiment of the present invention.
Fig. 3 is the block diagram of rear echo (post echo) processing module of the embodiment of the present invention.
Fig. 4 is the flow chart of the processing method of the quadrature carrier frequency division multiplexed signals of echo processing after the employing of the embodiment of the present invention.
Fig. 5 is the block diagram of pre-echo (pre echo) processing module of the embodiment of the present invention.
Fig. 6 is the flow chart of the processing method of the quadrature carrier frequency division multiplexed signals of the employing pre-echo process of the embodiment of the present invention.
Fig. 7 is the block diagram of the estimating apparatus of the special pilot frequency-region signal of the embodiment of the present invention.
Fig. 8 is the flow chart of the estimating and measuring method of the special pilot frequency-region signal of the embodiment of the present invention.
Description of reference numerals
1: receiver
11: receiving front-end circuit
12: echo mode selector
13: interference blanking unit
131,3: rear echo processing module
132,5: pre-echo processing module
2,304,308,315,504,508,515: balanced decision-making device
201,317,517: equalizer
202: pilot tone frequency domain signal generator
203: resolver
204: subtracter
205: comparator
206: square operation device
207,208: multiplexer
S401 ~ S413, S601 ~ 613, S801 ~ S805: steps flow chart
301,501: the first storage elements
302,502: the second storage elements
303,314,503,514: channel estimation device
305,506: multiplexer
306,505,7: special pilot frequency-region signal estimator
307,507: code border interference estimator
313,322,512,513,521: subtracter
309,316,509,516: interchannel interference estimator
310 ~ 312,318 ~ 320,510,511,523,518 ~ 520: Delay Element
321,522: adder
71: fast fourier transformer
72: sequence signal generator
7211: the first frequency reducing samplers
7212,7222: first-phase shifter
7213,7223: the first low pass filters
7214,7224: second-phase shifter
724: zero padding interpolation device
725: the first multiplexers
726: the second multiplexers
7221: the second frequency reducing samplers
73: specific pilot signal generator
731: third phase shifter
732: the second low pass filters
733: the four phase shift devices
734: multiplier
Embodiment
Hereafter describe various exemplary embodiments more fully with reference to the accompanying drawings, show some exemplary embodiments in the accompanying drawings.But concept of the present invention may embody in many different forms, and should not be construed as and be limited to set forth exemplary embodiment herein.
The embodiment of the present invention provides a kind of processing method of quadrature carrier frequency division multiplexed signals, and it is for the interference of blanking code border and interchannel interference (Inter-Channel Interference, ICI).The processing method of this quadrature carrier frequency division multiplexed signals adopts iteration (iteration) mode based on reliable decision region to realize, and it has lower cost and preferably performance.In addition, because the processing method system of above-mentioned quadrature carrier frequency division multiplexed signals processes for the quadrature carrier frequency division multiplexed signals on frequency domain, and in some cases, need to use special pilot frequency-region signal, therefore, the embodiment of the present invention additionally provides a kind of estimating and measuring method, device of special pilot frequency-region signal, special pilot frequency-region signal to estimate.
First, please refer to Fig. 1, Fig. 1 is the block diagram of the receiver of the embodiment of the present invention.Receiver 1 may be used in the digital television broadcasting system of DVB-T2 standard, but the present invention is not limited to this.Receiver 1 comprises receiving front-end circuit 11, echo mode selector 12 and interference blanking unit 13, and wherein, echo mode selector 12 is electrically connected interference blanking unit 13, and interference blanking unit 13 is electrically connected receiving front-end circuit 11.
Receiving front-end circuit 11 is for receiving the quadrature carrier frequency division multiplexed signals in time domain; and to the quadrature carrier frequency division multiplexed signals in time domain; and behind the protection interval removing the quadrature carrier frequency division multiplexed signals in time domain, obtain the quadrature carrier frequency division multiplexed signals on frequency domain by fast fourier transform.
Echo mode selector 12 is for exporting an echo mode signal ECHO_FLAG, and echo mode signal ECHO_FLAG is for representing that interference blanking unit 13 need adopt rear echo processing module 131 or pre-echo processing module 132 to eliminate the interference of code border and the interchannel interference of the quadrature carrier frequency division multiplexed signals that its frequency domain receives.The echo mode signal ECHO_FLAG that echo mode selector 12 exports can be decided in its sole discretion by receiving terminal user, or the echo mode selector 12 quadrature carrier frequency division multiplexed signals that can pass through in detection time domain learns that actual channel conditions is to determine echo mode signal ECHO_FLAG.
Interference blanking unit 13 comprises multiple above circuit, echo processing module 131 or pre-echo processing module 132 after becoming with configuration.In the embodiment of the present invention, rear echo processing module 131 or pre-echo processing module 132 can share some circuit, also can be two modules independent of each other.Even, rear echo processing module 131 or pre-echo processing module 132 can be a kind of digital signal processing circuits, and it processes the quadrature carrier frequency division multiplexed signals on the frequency domain received according to program code, to eliminate its yard of border interference and interchannel interference.
Interference blanking unit 13 can have storage element, such as static random access memory (Static Radom Access Memory, SRAM), to keep in the first signal and secondary signal respectively.After the quadrature carrier frequency division multiplexed signals of interference blanking unit 13 on the frequency domain received, described secondary signal being updated to the quadrature carrier frequency division multiplexed signals on described frequency domain, is former secondary signal by described first signal update.Then, interference blanking unit 13 carries out channel estimating according to described first signal and described secondary signal, and produce channel estimation result, namely also interference blanking unit 13 is that quadrature carrier frequency division multiplexed signals on use two frequency domains (receiving the quadrature carrier frequency division multiplexed signals on the frequency domain that receives with the last time after treatment at present) produces channel estimating result.At this, note that the implementation of carrying out channel estimating according to described first signal and described secondary signal can use current any use two signals to carry out the channel estimating and measuring method of channel estimating, and the present invention is not as limit.
As previously described, receiver 1 may be used in the digital television broadcasting system of second generation ground digital television broadcast standard.In the digital television broadcasting system of second generation ground digital television broadcast standard, a super frame (super frame) includes multiple T2 frame and multiple feature expansion frame part (Feature Extension Frame part, FEF part).Each T2 frame has multiple quadrature carrier frequency division multiplexed signals as pilot tone (comprising P1, P2 pilot tone time-domain signal) and multiplely (comprises general (normal) data and frame closes (Frame Closing as data, FC) data) quadrature carrier frequency division multiplexed signals, and feature expansion frame part only has a quadrature carrier frequency division multiplexed signals of P1 pilot tone time-domain signal and multiple quadrature carrier frequency division multiplexed signalss of feature expansion frame data.Therefore, when the quadrature carrier frequency division multiplexed signals on the frequency domain that the frame of quadrature carrier frequency division multiplexed signals on the frequency domain received is T2 frame and reception uses as P1 pilot tone frequency-region signal, then this special pilot frequency-region signal of P1 pilot tone frequency-region signal must be used as the benchmark of estimation code border interference result.At this, note that the implementation of estimation code border interference result can adopt at present for estimating a yard method for border interference result, and the present invention is not as limit.
In this embodiment, can use frame activation signal and special pilot activation signal represent respectively the frame of the quadrature carrier frequency division multiplexed signals on the frequency domain of reception be whether T2 frame and reception frequency domain on quadrature carrier frequency division multiplexed signals whether use as P1 pilot tone frequency-region signal.When particular frame activation signal and special pilot activation signal are very, also the frame of quadrature carrier frequency division multiplexed signals namely judging on the frequency domain that receives is T2 frame and quadrature carrier frequency division multiplexed signals on the frequency domain received uses as P1 pilot tone frequency-region signal, then interference blanking unit 13 uses P1 pilot tone frequency-region signal to estimate this yard of border interference result based on described channel estimating result.
On the contrary, when particular frame activation signal or special pilot activation signal are non-real, also namely judge that the frame of the quadrature carrier frequency division multiplexed signals on the frequency domain that receives is not as the quadrature carrier frequency division multiplexed signals on the frequency domain of T2 frame or reception uses as P1 pilot tone frequency-region signal, then interference blanking unit 13 uses described first signal or described secondary signal to estimate a yard border interference result based on described channel estimating result, wherein, choice for use first signal or secondary signal decide according to echo mode signal ECHO_FLAG.When echo mode signal ECHO_FLAG need adopt rear echo processing module 131 for representing interference blanking unit 13, interference blanking unit 13 uses the first signal-information road estimation result to produce code border interference result.When echo mode signal ECHO_FLAG need adopt pre-echo processing module 132 for representing interference blanking unit 13, interference blanking unit 13 uses secondary signal and channel estimating result to produce code border and disturbs result.
After acquisition described code border interference result, interference blanking unit 13 upgrades described secondary signal or the first signal according to described code border interference result, and wherein choice for use first signal or secondary signal decide according to echo mode signal ECHO_FLAG.When echo mode signal ECHO_FLAG need adopt rear echo processing module 131 for representing interference blanking unit 13, what secondary signal was updated to that former secondary signal deducts yard border interference result subtracts each other result, and the first signal then remains unchanged.When echo mode signal ECHO_FLAG need adopt pre-echo processing module 132 for representing interference blanking unit 13, what the first signal was updated to that former first signal deducts yard border interference result subtracts each other result, and secondary signal then remains unchanged.
Then, interference blanking unit 13 based on described secondary signal or the first signal, and disturbs result based between described channel estimation result estimation first passage, and wherein, choice for use first signal or secondary signal decide according to echo mode signal ECHO_FLAG.When echo mode signal ECHO_FLAG need adopt rear echo processing module 131 for representing interference blanking unit 13, interference blanking unit 13 uses secondary signal and channel estimating result to produce between first passage and disturbs result.When echo mode signal ECHO_FLAG need adopt pre-echo processing module 131 for representing interference blanking unit 13, interference blanking unit 13 uses the first signal-information road estimation result to produce between first passage and disturbs result.
Then, interference blanking unit 13 is based on described secondary signal or the first signal, and based on disturbing result and described channel estimation result between described first passage, disturb result between estimation second channel, wherein choice for use first signal or secondary signal decide according to echo mode signal ECHO_FLAG.When echo mode signal ECHO_FLAG need adopt rear echo processing module 131 for representing interference blanking unit 13, interference blanking unit 13 uses secondary signal based on disturbing result and described channel estimation result between described first passage, estimates between second channel and disturbs result.When echo mode signal ECHO_FLAG need adopt pre-echo processing module 131 for representing interference blanking unit 13, interference blanking unit 13 uses the first signal based on disturbing result and described channel estimation result between described first passage, estimates between second channel and disturbs result.At this, note that realizing estimation interchannel interference can adopt at present for estimating the method for interchannel interference in the mode obtaining first and second interchannel interference result, and the present invention is not as limit.
Then, interference blanking unit 13 is based on according to disturbing result to upgrade described secondary signal or the first signal between described second channel, wherein, choice for use first signal or secondary signal decide according to echo mode signal.When echo mode signal ECHO_FLAG need adopt rear echo processing module 131 for representing interference blanking unit 13, interference blanking unit 13 secondary signal is updated to former secondary signal deduct to disturb result between second channel subtract each other result.When echo mode signal ECHO_FLAG need adopt pre-echo processing module 131 for representing interference blanking unit 13, described first signal update is that the first signal stored at present adds and disturbs result between second channel and deduct the result of calculation disturbing result between first passage by interference blanking unit 13.
Afterwards, interference blanking unit 13 carries out equilibrium treatment to the first signal, and exports the first signal after equilibrium treatment.By above-mentioned process, the quadrature carrier frequency division multiplexed signals on the frequency domain of reception is processed repeatly by above-mentioned, and will become the first signal after equilibrium treatment, and its yard of border interference also can be eliminated by this with interchannel interference.
At this, please note, before above-mentioned generation code border interference result and first, second interchannel interference result, balanced process with decision-making (equalization and decision), to obtain the first signal after balanced and decision-making treatment and secondary signal is first passed through with secondary signal by the first signal used.Then, balanced with decision-making treatment after the first signal and secondary signal just understand be brought and estimate code border and disturb result and first, second interchannel interference result.In other words, the processing method of quadrature carrier frequency division multiplexed signals that interference blanking unit 13 adopts adopts reliable decision region to guarantee the accuracy of yard border interference result and first, second interchannel interference result.About the balanced details with decision-making treatment, in describing in detail afterwards, just first will not repeat at this.
Can learn from above, the processing method of the quadrature carrier frequency division multiplexed signals that interference blanking unit 13 adopts processes for the quadrature carrier frequency division multiplexed signals on frequency domain completely, therefore can avoid using fast fourier transform repeatedly and inverse fast fourier transform.In addition, under specific circumstances, P1 pilot tone frequency-region signal also can produce interference, and therefore, interference blanking unit 13 also can be estimated voluntarily and P1 pilot tone frequency-region signal, and produces code border interference estimation result accordingly.In addition, the processing method of above-mentioned quadrature carrier frequency division multiplexed signals carries out twice iterative processing to the quadrature carrier frequency division multiplexed signals on frequency domain, two quadrature carrier frequency division multiplexed signalss are used to carry out estimated channel, and be the method adopting reliable decision region and pilot aided to adjudicate, therefore can effectively disturb and interchannel interference on blanking code border, and elevator system usefulness.In addition, the processing method of quadrature carrier frequency division multiplexed signals can adopt pre-echo process or rear echo processing, and pre-echo process or rear echo processing can the assemblies of shared portion, therefore its hardware spending can not increase too many.
In the embodiment of the present invention, rear echo processing module can have balanced decision-making device with pre-echo processing module, with before estimation code border interference result and first, second interchannel interference result, to first balanced and decision-making treatment will be carried out by use first signal with secondary signal, re-use through balanced with decision-making treatment after the first signal and secondary signal estimate yard border and disturb result and first, second interchannel interference result.The implementation of wherein a kind of balanced decision-making device will be introduced below, but the present invention is not restricted to this.
Please refer to Fig. 2, Fig. 2 is the block diagram of the balanced decision-making device of the embodiment of the present invention.Balanced decision-making device 2 comprises equalizer 201, pilot tone frequency domain signal generator 202, resolver (slicer) 203, subtracter 204, comparator 205, square operation device 206, multiplexer 207 and 208.Equalizer 201 is electrically connected subtracter 204, resolver 203 and multiplexer 207, and resolver 203 is electrically connected multiplexer 206 and subtracter 204, and subtracter 204 is electrically connected square operation device 206.Comparator 205 is electrically connected multiplexer 207, and multiplexer 207 is electrically connected multiplexer 208, and pilot tone frequency domain signal generator 202 is electrically connected multiplexer 208.
Equalizer 201 receives input signal and channel estimating result, and carries out equilibrium treatment according to channel estimation result to input signal, and wherein, input signal can be the first signal, secondary signal, the first signal after treatment or secondary signal after treatment.Resolver 203, according to the input signal after equilibrium treatment, exports the input signal after decision-making.Input signal is deducted the input signal after corresponding decision-making by subtracter 204, with produce through before decision-making treatment and after input signal between difference (being essentially vector difference).
Square operation device 206 receives the difference that subtracter 204 exports, and calculate the absolute value of difference square.Comparator 205 compares operation result and the threshold value of square operation device 206 output, and produces comparative result accordingly.Multiplexer 207 exports the input signal after equilibrium or the input signal after decision-making according to comparative result.If the absolute value of difference square be greater than threshold value, then multiplexer 207 exports the input signal after equilibrium.If the absolute value of difference square be less than or equal to threshold value, then export the input signal after decision-making.
Pilot tone frequency domain signal generator 202 receives input signal, and produces corresponding pilot tone frequency-region signal accordingly.Multiplexer 208 according to input signal whether for pilot tone frequency domain signal deciding exports pilot tone frequency-region signal that pilot tone frequency domain signal generator 202 produces or the signal that multiplexer 207 exports.
If input signal is pilot tone frequency-region signal, then the pilot tone frequency-region signal that pilot tone frequency domain signal generator 202 produces by multiplexer 208 exports as the input signal after equilibrium with decision-making treatment.If input signal is not pilot tone frequency-region signal, then the signal that multiplexer 207 exports by multiplexer 208 exports as the input signal after equilibrium with decision-making treatment.
Then, wherein a kind of implementation of rear echo processing module will be introduced.It is, however, to be noted that the implementation of following rear echo processing module is not for limiting the present invention.
Refer to Fig. 3, Fig. 3 is the block diagram of the rear echo processing module of the embodiment of the present invention.Rear echo processing module 3 comprise the first storage element 301, second storage element 302, channel estimator 303,314, balanced decision-making device 304,308,315, multiplexer 305, special pilot frequency-region signal estimator 306, code border interference estimator 307, subtracter 313,322, interchannel interference estimator 309,316, Delay Element 310 ~ 312,318 ~ 320, equalizer 317 and adder 321.
In this embodiment, the first storage element 301 is electrically connected the second storage element 302, and channel estimator 303 is electrically connected the first storage element 301 and the second storage element 302.Balanced decision-making device 304 is electrically connected channel estimation device 303 and the first storage element 301, and multiplexer 305 is electrically connected channel estimation device 303 and special pilot frequency-region signal estimator 306.Interference estimator 307 in code border is electrically connected channel estimation device 303 and multiplexer 305, and Delay Element 310 is electrically connected channel estimator 303.Delay Element 311 is electrically connected Delay Element 310, and balanced decision-making device 308 is electrically connected Delay Element 310 and the second storage element 302.Subtracter 313 is electrically connected code border interference estimator 307 and the second storage element 313.Interchannel interference estimator 309 is electrically connected Delay Element 311 and balanced decision-making device 308, and Delay Element 312 is electrically connected interchannel interference estimator 309.
Channel estimation device 314 is electrically connected the first storage element 301 and the second storage element 302, and adder 321 is electrically connected the second storage element 302 and Delay Element 312.Subtracter 322 is electrically connected the second storage element 302 and interchannel interference estimator 316, and Delay Element 318 is electrically connected channel estimator 314.Delay Element 319 is electrically connected Delay Element 318, and balanced decision-making device 315 is electrically connected adder 321 and Delay Element 318.Delay Element 320 is electrically connected Delay Element 319.Equalizer 317 is electrically connected the first storage element 301 and Delay Element 320, and interchannel interference estimator 316 is electrically connected balanced decision-making device 315 and Delay Element 319.
Note that the annexation of each assembly in above-mentioned rear echo processing module 3 and implementation are not for limiting the present invention at this.For example, by the setting of other multiplexers, the those of ordinary skill in this field should learn in first time interative computation can be same with the members that uses in the process of second time interative computation, to save the expense of hardware.
Referring to Fig. 3 and Fig. 4, Fig. 4 is the flow chart of the processing method of the quadrature carrier frequency division multiplexed signals of echo processing after the employing of the embodiment of the present invention.The processing method of the quadrature carrier frequency division multiplexed signals of echo processing after the employing of Fig. 4 can be executed in the rear echo processing module 3 of Fig. 3, but it should be noted that, the processing method of the quadrature carrier frequency division multiplexed signals of echo processing after the employing of Fig. 4 also can be executed in the rear echo processing module of other implementations, be only the description repeated with omission for convenience of description herein, just the function of each for Fig. 3 assembly and each step of Fig. 4 be incorporated in and hereinafter describe in the lump.
In Fig. 4, the process of interative computation comprises step S401 ~ S408 for the first time.First, in step S401, rear echo processing module 3 receives the quadrature carrier frequency division multiplexed signals on frequency domain.Then, in step S402, the secondary signal that second storage element 302 is stored is updated to the quadrature carrier frequency division multiplexed signals on frequency domain that rear echo processing module 3 receives, and its first signal update is the former secondary signal that the second storage element 302 stores by the first storage element 301.Then, in step S403, channel estimation device 303 receives the first signal and secondary signal, carries out channel estimating, and produce channel estimation result according to described first signal and described secondary signal.Then, in step s 404, balanced decision-making device 304 carries out equilibrium and decision-making treatment according to channel estimation result for the first signal, to produce the first signal after equilibrium with decision-making treatment, and special pilot frequency-region signal estimator 306 produces special pilot frequency-region signal P1_F_D (such as P1 pilot tone frequency-region signal).The mode of the first signal being carried out to equilibrium and decision-making treatment can be learnt by the related description of Fig. 2.In addition, the mode producing special pilot frequency-region signal P1_F_D is relevant with system standard, the producing method of such as P1 pilot tone time-domain signal and its block diagram have been specified in the standard of DVB-T2, and special pilot frequency-region signal estimator 306 can be estimated according to P1 pilot tone time-domain signal and P1 pilot tone frequency-region signal, its correlative detail will be described later, and first omits at this.
Then, in step S405, multiplexer 305 exports the first signal after special pilot frequency-region signal P1_F_D or balanced and decision-making according to particular frame activation signal and special pilot activation signal, and code border interference estimator 307 according to particular frame activation signal or special pilot activation signal produce receive special pilot frequency-region signal P1_F_D or balanced with decision-making after the first signal, and produce corresponding code border according to channel estimating result and disturb result.Furthermore, when particular frame activation signal (such as, T2 frame activation signal T2_ENB) and special pilot activation signal is (such as, P1 pilot tone activation signal P1_ENB) be very, code border interference estimator 307 is estimated yard border based on special pilot frequency-region signal P1_F_D and described channel estimation result and is disturbed result.When particular frame activation signal or special pilot activation signal are non-real, code border interference estimator 307 estimates result based on the first signal-information road after balanced and decision-making, estimation code border interference result.
Then, in step S406, secondary signal is deducted a yard border interference result by subtracter 313, and the second storage element 302 secondary signal is updated to secondary signal deducts yard border interference result subtract each other result.Then, in step S 407, Delay Element 310 delayedchannel estimation result, the channel estimation result postponed gives balanced decision-making device 308 and Delay Element 311, and balanced decision-making device 308 receives secondary signal, and according to channel estimating result, equilibrium and decision-making treatment are carried out to secondary signal, to produce the secondary signal after equilibrium with decision-making treatment.The mode of secondary signal being carried out to equilibrium and decision-making treatment can be learnt by the related description of Fig. 2, therefore does not repeat them here.
Then, in step S408, Delay Element 311 postpones its channel estimation result received, the channel estimation result postponed gives interchannel interference estimator 309, and interchannel interference estimator 309 produces between first passage based on the secondary signal after balanced and decision-making and channel estimating result and disturbs result, then, disturb result between the first passage that Delay Element 312 delay receives, and give adder 321 by delay first interchannel interference result.In this, first time interative computation finally estimate between first passage and disturb result, and the secondary signal that the second storage element 302 stores has deducted a yard border interference result.
In Fig. 4, the process of second time interative computation comprises step S409 ~ S413.In step S409, channel estimation device 303 disturbs the secondary signal of result to carry out channel estimating according to not deducting yard border in the first signal and the second storage element 502, and produces channel estimation result.In other words, the channel estimation result that produces of step S409 is identical with the channel estimation result that step S403 produces.
Then, in step S410, adder 321 will deduct yard secondary signal of border interference result and a first interchannel interference results added stored by second storage element 302, the channel estimation result that Delay Element 318 delayedchannel estimator 314 exports, and the channel estimation result postponed gives balanced decision-making device 315 and Delay Element 319, and balanced decision-making device 315 carries out described equilibrium and decision-making treatment according to channel estimation result to addition result, to produce the addition result after equilibrium with decision-making treatment process.The mode of addition result being carried out to equilibrium and decision-making treatment can be learnt by the related description of Fig. 2, therefore does not repeat them here.
Then, in step S411, Delay Element 319 postpones the channel estimating result received, and the channel estimation result postponed gives interchannel interference estimator 316 and Delay Element 320, and interchannel interference estimator 316 is estimated between second channel based on the addition result after balanced and decision-making and channel estimation result and is disturbed result.Then, in step S412, secondary signal deducts between second channel and disturbs result by subtracter 322, and the secondary signal that the second storage element 302 is stored be updated to secondary signal deduct to disturb result between second channel subtract each other result.Afterwards, in step S413, Delay Element 320 postpones the channel estimating result received, and the channel estimation result postponed gives equalizer 317, and equalizer 317 carries out equilibrium treatment according to channel estimation result to the first signal stored by the first storage element 301.
In this, second time interative computation is finally estimated between second channel and is disturbed result, and the secondary signal that the second storage element 302 stores also deducts interchannel interference result except deducting yard border interference result.In addition, the first signal stored by the first storage element 301 is essentially the last secondary signal received after treatment, and therefore, the first signal after the equilibrium now exported, itself has also deducted code border interference result and interchannel interference result.Therefore, the processing method of the quadrature carrier frequency division multiplexed signals of Fig. 4 that adopts of rear echo processing module 3 can the interference of blanking code border and interchannel interference effectively.
Then, wherein a kind of implementation of pre-echo processing module will be introduced.It is, however, to be noted that the implementation of following pre-echo processing module is not for limiting the present invention.
Refer to Fig. 5, Fig. 5 is the block diagram of the pre-echo processing module of the embodiment of the present invention.Rear echo processing module 5 comprise the first storage element 501, second storage element 502, channel estimator 503,514, balanced decision-making device 504,508,515, special pilot frequency-region signal estimator 505, multiplexer 506, code border interference estimator 507, interchannel interference estimator 509,516, subtracter 512,513,521, Delay Element 510,511,523,518 ~ 320, equalizer 517 and adder 522.
In this embodiment, the first storage element 501 is electrically connected the second storage element 502 and subtracter 513, and channel estimation device 503 is electrically connected the first storage element 501 and the second storage element 502.Balanced decision-making device 504 is electrically connected channel estimation device 503 and the second storage element 502, and multiplexer 506 is electrically connected channel estimation device 504 and special pilot frequency-region signal estimator 505.Interference estimator 507 in code border is electrically connected channel estimation device 503 and multiplexer 506, and Delay Element 510 is electrically connected channel estimator 503.Delay Element 523 is electrically connected Delay Element 510, and balanced decision-making device 508 is electrically connected Delay Element 310 and the first storage element 501.Delay Element 523 is electrically connected Delay Element 510, and subtracter 513 is electrically connected code border interference estimator 509, and subtracter 512 is electrically connected the first storage element 501 and disturbs estimator 507 with code border.Interchannel interference estimator 509 is electrically connected Delay Element 523 and balanced decision-making device 508, and Delay Element 511 is electrically connected interchannel interference estimator 509.
Channel estimation device 514 is electrically connected the first storage element 501 and the second storage element 502, and adder 522 is electrically connected the first storage element 501 and subtracter 521.Subtracter 521 is electrically connected Delay Element 511 and interchannel interference estimator 516, and Delay Element 518 is electrically connected channel estimator 514.Delay Element 519 is electrically connected Delay Element 518, and balanced decision-making device 515 is electrically connected the first storage element 501 and Delay Element 518.Delay Element 520 is electrically connected Delay Element 519.Equalizer 517 is electrically connected the first storage element 501 and Delay Element 520, and interchannel interference estimator 516 is electrically connected balanced decision-making device 515 and Delay Element 519.
At this, note that the annexation of each assembly in above-mentioned rear front sonication module 5 and implementation are not for limiting the present invention.For example, by the setting of other multiplexers, the those of ordinary skill in this field should learn in first time interative computation can be same with the members that uses in the process of second time interative computation, to save the expense of hardware.
Referring to Fig. 5 and Fig. 6, Fig. 6 is the flow chart of the processing method of the quadrature carrier frequency division multiplexed signals of the employing pre-echo process of the embodiment of the present invention.The processing method of the quadrature carrier frequency division multiplexed signals of echo processing after the employing of Fig. 6 can be executed in the pre-echo processing module 5 of Fig. 5, but it should be noted that, the processing method of the quadrature carrier frequency division multiplexed signals of echo processing after the employing of Fig. 6 also can be executed in the rear echo processing module of other implementations, be only the description repeated with omission for convenience of description herein, just the function of each for Fig. 5 assembly and each step of Fig. 6 be incorporated in and hereinafter describe in the lump.
In Fig. 6, the process of interative computation comprises step S601 ~ S608 for the first time.First, in step s 601, rear echo processing module 5 receives the quadrature carrier frequency division multiplexed signals on frequency domain.Then, in step S602, the secondary signal that second storage element 602 is stored is updated to the quadrature carrier frequency division multiplexed signals on frequency domain that rear echo processing module 5 receives, and its first signal update is the former secondary signal that the second storage element 502 stores by the first storage element 501.Then, in step S603, channel estimation device 503 receives the first signal and secondary signal, carries out channel estimating, and produce channel estimation result according to described first signal and described secondary signal.Then, in step s 604, balanced decision-making device 504 carries out equilibrium and decision-making treatment according to channel estimation result for secondary signal, to produce the secondary signal after equilibrium with decision-making treatment, and special pilot frequency-region signal estimator 505 produces special pilot frequency-region signal P1_F_D (such as P1 pilot tone frequency-region signal).The mode of secondary signal being carried out to equilibrium and decision-making treatment can be learnt by the related description of Fig. 2.In addition, the mode producing special pilot frequency-region signal P1_F_D is relevant with system standard, the producing method of such as P1 pilot tone frequency-region signal and its block diagram have been specified in the standard of DVB-T2, and special pilot frequency-region signal estimator 306 can be estimated according to P1 pilot tone time-domain signal and P1 pilot tone frequency-region signal, its correlative detail will be described later, and first omits at this.
Then, in step s 605, multiplexer 506 exports the secondary signal after special pilot frequency-region signal P1_F_D or balanced and decision-making according to particular frame activation signal and special pilot activation signal, and code border interference estimator 507 according to particular frame activation signal or special pilot activation signal produce receive special pilot frequency-region signal P1_F_D or balanced with decision-making after secondary signal, and produce corresponding code border according to channel estimating result and disturb result.Furthermore, when particular frame activation signal (such as, T2 frame activation signal T2_ENB) and special pilot activation signal is (such as, P1 pilot tone activation signal P1_ENB) be very, code border interference estimator 507 is estimated yard border based on special pilot frequency-region signal P1_F_D and described channel estimation result and is disturbed result.When particular frame activation signal or special pilot activation signal are non-real, code border interference estimator 507 estimates result based on the first signal-information road after balanced and decision-making, estimation code border interference result.
Then, in step S606, the first signal is deducted a yard border interference result by subtracter 512, and the first signal update is the first signal by the first storage element 501 deduct yard border interference result subtract each other result.Then, in step S607, Delay Element 510 delayedchannel estimation result, the channel estimation result postponed gives balanced decision-making device 508 and Delay Element 523, and balanced decision-making device 508 receives the first signal, and according to channel estimating result, equilibrium and decision-making treatment are carried out to the first signal, to produce the first signal after equilibrium with decision-making treatment.The mode of the first signal being carried out to equilibrium and decision-making treatment can be learnt by the related description of Fig. 2, therefore does not repeat them here.
Then, in step S608, Delay Element 523 postpones its channel estimation result received, the channel estimation result postponed gives interchannel interference estimator 509, and interchannel interference estimator 509 is estimated result based on the first signal-information road after balanced and decision-making and is produced between first passage and disturb result, then, subtracter 513 and Delay Element 511 receive the first interchannel interference result, Delay Element 511 postpones to disturb result to give adder 521 between the first interchannel interference result and the first passage that postponed, first signal is deducted the first interchannel interference result by subtracter 513, and the first signal update that the first storage element 501 is stored is the first signal deduct the first interchannel interference result subtract each other result.In this, first time interative computation finally estimate between first passage and disturb result, and the first signal that the first storage element 501 stores has deducted and yard has disturbed result between border interference result and first passage.
In Fig. 6, the process of second time interative computation comprises step S609 ~ S613.In step S609, channel estimation device 603 disturbs between result and first passage disturb the first signal of result to carry out channel estimating according to not deducting yard border in secondary signal and the first storage element 501, and produces channel estimation result.In other words, the channel estimation result that produces of step S609 is identical with the channel estimation result that step S603 produces.
Then, in step S610, Delay Element 518 postpones the channel estimating result received, and the channel estimation result postponed gives balanced decision-making device 515 and Delay Element 519, balanced decision-making device 515 carries out described balanced and decision-making treatment, to produce the first signal after equilibrium with decision-making treatment process according to channel estimation result to the first signal (the first signal now has deducted a yard border interference result and disturbed result with between first passage) stored by the first storage element 501.The mode of the first signal being carried out to equilibrium and decision-making treatment can be learnt by the related description of Fig. 2, therefore does not repeat them here.
Then, in step s 611, Delay Element 519 postpones the channel estimating result received, and the channel estimation result postponed gives interchannel interference estimator 516 and Delay Element 520, and interchannel interference estimator 516 is estimated result based on the first signal-information road after balanced and decision-making and is estimated between second channel and disturb result, then, subtracter 521 disturbs result by disturbing result to deduct between first passage between second channel, to obtain its difference.Then, in step S612, first signal adds by adder 522 disturbs result to deduct the difference disturbing result between first passage between second channel, and the first signal update is the first signal by the first storage element 501 adds and disturb result to deduct the result of calculation of the difference disturbing result between first passage between second channel, also namely the first signal is updated to the first signal stored at present and adds and to disturb between second channel and to deduct the result of calculation disturbed between first passage.Afterwards, in step S613, Delay Element 520 postpones the channel estimating result received, and the channel estimation result postponed gives equalizer 517, and equalizer 517 carries out equilibrium treatment according to channel estimation result to the first signal stored by the first storage element 501.
In this, second time interative computation is finally estimated between second channel and is disturbed result, and the first signal that the first storage element 501 stores also deducts interchannel interference result except deducting yard border interference result.In addition, the first signal stored by the first storage element 301 because through process, so time the equilibrium that exports after the first signal, itself also deducted code border interference result and interchannel interference result.Therefore, the processing method of the quadrature carrier frequency division multiplexed signals of Fig. 6 that adopts of pre-echo processing module 5 can the interference of blanking code border and interchannel interference effectively.
Then, please refer to Fig. 7, Fig. 7 is the block diagram of the estimating apparatus of the special pilot frequency-region signal of the embodiment of the present invention.The estimating apparatus 7 of special pilot frequency-region signal described special pilot frequency-region signal P1_F_D for estimating.The estimating apparatus 7 of special pilot frequency-region signal comprises fast fourier transformer 71, sequence signal processor 72 and the special pilot frequency-region signal generator 73 of at 2048, sequence signal processor 72 described in fast fourier transformer 71 electric property coupling of wherein said 2048, and special pilot frequency-region signal generator 73 described in described sequence signal processor 72 electric property coupling.
Referring to Fig. 7 and Fig. 8, Fig. 8 is the flow chart of the estimating and measuring method of the special pilot frequency-region signal of the embodiment of the present invention.First, in step S801, the fast fourier transformer 71 of 2048 obtains special pilot time-domain signal P1_T_D, wherein the producing method of special pilot time-domain signal P1_T_D can with reference to the standard of each system, such as, explain how to produce P1 pilot tone time-domain signal in ground two generation ground system of digital television broadcast standard, therefore in the present invention, will the producing method of special pilot time-domain signal P1_T_D do not repeated.Then, in step S802, fast fourier transformer 71 couples of special pilot time-domain signal P1_T_D of 2048 carry out the fast fourier transform of 2048, to obtain the First ray signal of 2048.Afterwards, in step S803, sequence signal processor 72 pairs of First ray signals process, with produce 1024 second and the 3rd sequence signal be greater than the 4th sequence signal of 2048.Then, in step S804, sequence signal processor 72 chooses first to fourth sequence signal as the 5th sequence signal according to echo mode signal ECHO_FLAG and fast fourier transform mode signal FFT_MOD, wherein fast fourier transform mode signal FFT_MOD is for representing the length (that is, carry out counting of computing) of the inverse fast fourier transform of current digital television broadcasting system use.Finally, in step S805, special pilot frequency-region signal generator 73 processes the 5th sequence signal, to produce special pilot frequency-region signal P1_F_D.
Please note at this, although, above-mentioned special pilot frequency-region signal P1_F_D can be used for the processing method of quadrature carrier frequency division multiplexed signals above to use, but the present invention does not limit above-mentioned special pilot frequency-region signal P1_F_D only can be used for the processing method of quadrature carrier frequency division multiplexed signals above to use.In other words, other devices or method use above-mentioned special pilot frequency-region signal P1_F_D if necessary, and the estimating and measuring method of above-mentioned special pilot frequency-region signal and device can also be used to produce described special pilot frequency-region signal P1_F_D.
In step S803, the specification specified how producing the second to the 4th sequence signal is as follows.Sequence signal processor 72 pairs of First ray signals carry out first and second frequency reducing sampling process of 0.5 frequency multiplication, obtain first and second frequency reducing sampling sequence signal respectively to obtain, wherein first and second frequency reducing sampling process system obtains multiple odd point of First ray signal and multiple signal values of even number point respectively.In other words, the second sequence signal comprises the signal value of all odd points of First ray signal, and the 3rd sequence signal comprises the signal value of all even number points of First ray signal.Then, sequence signal processor 72 sequentially carries out first-phase displacement process, the first low-pass filtering treatment and second-phase displacement process to first and second frequency reducing sampling sequence signal again, to produce second and the 3rd sequence signal of respectively at 1024.In addition, sequence signal processor 72 also can carry out zero padding interpolation processing to First ray signal, to produce the 4th sequence signal being greater than 2048 points (such as 4096 points).
In step S804, how to choose first to fourth sequence signal as follows as the specification specified of the 5th sequence signal.When fast fourier transform mode signal FFT_MOD represents that the length of the inverse fast fourier transform of current digital television broadcasting system use is 1024 points, and echo mode signal ECHO_FLAG represents and adopt pre-echo process, then sequence signal processor 72 the 5th sequence signal that selection second sequence signal is exported as it.When fast fourier transform mode signal FFT_MOD represents that the length of the inverse fast fourier transform of current digital television broadcasting system use is 1024 points, and echo mode signal ECHO_FLAG represents and adopt rear echo processing, then sequence signal processor 72 the 5th sequence signal that selection the 3rd sequence signal is exported as it.When fast fourier transform mode signal FFT_MOD represents that the length of the inverse fast fourier transform of current digital television broadcasting system use is 2048 points, then sequence signal processor 72 will select the 5th sequence signal that First ray signal exports as it.When fast fourier transform mode signal FFT_MOD represents that the length of the inverse fast fourier transform of current digital television broadcasting system use is for being greater than 2048 points, then sequence signal processor 72 the 5th sequence signal that selection the 4th sequence signal is exported as it.
In step S805, the specification specified how producing special pilot frequency-region signal P1_F_D is as follows.Special pilot frequency-region signal generator 73 carries out after third phase displacement process, the second low-pass filtering treatment, the 4th phase shift process to be multiplied with norm and to process, described special pilot frequency-region signal P1_F_D to estimate to the 5th sequence signal in order.
Please then continue with reference to Fig. 7, the detailed implementation of sequence signal processor 72 is described as follows, but the present invention does not limit the actual practice of sequence signal processor 72 with following implementation.Sequence signal processor 72 include 0.5 frequency multiplication first and second frequency reducing sampler 7211,7221, first-phase shifter 7212,7222, first low pass filter 7213,7223, second-phase shifter 7214,7224, zero padding interpolation device 724 and first and second multiplexer 725,726.The fast fourier transformer 71 of first and second frequency reducing sampler 7211 electric property coupling 2048, and difference electric property coupling first low pass filter 7213,7223.First low pass filter 7213,7223 is electric property coupling first low pass filter 7213,7223 respectively, and the first low pass filter 7213,7223 electric property coupling second-phase shifter 7214,7224 respectively.First multiplexer 725 electric property coupling second-phase shifter 7214,7224.The fast fourier transformer 71 of zero padding interpolation device 724 electric property coupling 2048.Second multiplexer 726 electric property coupling first multiplexer 725,2048 fast fourier transformer 71, zero padding interpolation device 724 and special pilot frequency-region signal generator 73.
First and second frequency reducing sampler 7211,7221 of 0.5 frequency multiplication is respectively used to first and second frequency reducing sampling process First ray signal being carried out to 0.5 frequency multiplication, obtains first and second frequency reducing sampling sequence signal respectively to obtain.First-phase shifter 7212,7222 is respectively used to carry out first-phase displacement process to first and second frequency reducing sampling sequence signal, namely by phase rotating first special angle of first and second frequency reducing sampling sequence signal, and in this embodiment, above-mentioned first special angle is 2 π (512/N), and wherein N is 2048.First low pass filter 7213,7223 is respectively used to carry out the first low-pass filtering treatment, to eliminate unnecessary high-frequency noise to first and second frequency reducing sampling sequence signal after first-phase displacement process.Second-phase shifter 7214,7224 is respectively used to carry out second-phase displacement process process to first and second frequency reducing sampling sequence signal after the first low-pass filtering treatment, to produce second and the 3rd sequence signal, namely by phase rotating second special angle to first and second frequency reducing sampling sequence signal after the first low-pass filtering treatment, and in this embodiment, above-mentioned second special angle is 2 π (-512/N).
Zero padding interpolation device 724 for the signal value of multiple zero being inserted between the odd point of First ray signal and the signal value of even number point, to produce the 4th sequence signal being greater than at 2048.First multiplexer 725 selects output second or the 3rd sequence signal according to echo mode signal ECHO_FLAG.Second multiplexer 726 is the 5th sequence signal selecting the output of the first multiplexer 725, First ray signal or the 4th sequence signal to export as it according to fast fourier transform mode signal FFT_MOD.
In addition, the detailed implementation of special pilot frequency-region signal generator 73 is described as follows, but the present invention does not limit the actual practice of special pilot frequency-region signal generator 73 with following implementation.Special pilot frequency-region signal generator 73 comprises third phase shifter 731, second low pass filter 732, the 4th phase shift device 733 and multiplier 734.Third phase shifter 731 electric property coupling sequence signal processor 72, to receive the 5th sequence signal, and the second low pass filter 732 electric property coupling third phase shifter 731.4th phase shift device 733 electric property coupling second low pass filter 732, and multiplier 734 electric property coupling the 4th phase shift device 733.
Third phase shifter 731 is for carrying out third phase displacement process to the 5th sequence signal, and namely by phase rotating the 3rd special angle of the 5th sequence signal, and in this embodiment, above-mentioned 3rd special angle is 2 π (1024/N).Second low pass filter 732 is for carrying out the second low-pass filtering treatment, to eliminate unnecessary high-frequency noise to the 5th sequence signal after third phase displacement process.4th phase shift device 733 is for carrying out the 4th phase shift process to the 5th sequence signal after the second low-pass filtering treatment, namely by phase rotating the 4th special angle of the 5th sequence signal after the second low-pass filtering treatment, and in this embodiment, above-mentioned 4th special angle is 2 π (1024/N).Then, the 5th sequence signal after the 4th phase shift process is multiplied by a norm NORM_VALUE by multiplier 734, to be multiplied process, and to produce special pilot frequency-region signal P1_F_D to carry out norm to the 5th sequence signal after the 4th phase shift process.
Note that the length of above-mentioned fast fourier transformer 71, the length of each sequence signal and each special angle system adopt second generation terrestrial DTV to be described for digital television broadcasting system at this.Have in art and usually know the knowledgeable, when in the standard of different digital television broadcasting systems, the length of above-mentioned fast fourier transformer 71, the length of each sequence signal and each special angle being designed.
Comprehensive the above, embodiments provide a kind of processing method for quadrature carrier frequency division multiplexed signals, it use that interative computation, reliable decision region and pilot aided are adjudicated, process on simple frequency domain, use the means such as two signal estimated channel to come blanking code border to disturb and interchannel interference, therefore its system effectiveness is better, and can avoid using repeatedly fast fourier transform and inverse fast fourier transform, therefore hardware spending and amount of calculation lower.In addition, the processing method of described quadrature carrier frequency division multiplexed signals can adopt pre-echo process or rear echo processing to come for the interference of different actual conditions blanking code borders and interchannel interference, and the mode of pre-echo process or rear echo processing is similar, even multiple assembly can be shared each other, therefore not too can increase hardware spending.In addition, the embodiment of the present invention additionally provides a kind of estimating and measuring method, device of special pilot frequency-region signal, and it can be estimated and described special pilot frequency-region signal, and the processing method for described quadrature carrier frequency division multiplexed signals uses.
The above, be only exemplary embodiments of the present invention, and the feature of only the present invention is not limited thereto, and is anyly familiar with this those skilled in the art in the field of the present invention, can think easily and change or modification, all can be encompassed in the scope of the claims of following this case.
Claims (22)
1. a processing method for quadrature carrier frequency division multiplexed signals, for the interference of blanking code border and interchannel interference, it is characterized in that, the processing method of described quadrature carrier frequency division multiplexed signals comprises:
Temporary first signal and secondary signal respectively;
Receive the quadrature carrier frequency division multiplexed signals on frequency domain, described secondary signal being updated to the quadrature carrier frequency division multiplexed signals on described frequency domain, is former secondary signal by described first signal update;
Carry out channel estimating according to described first signal and described secondary signal, and produce channel estimation result;
When particular frame activation signal or special pilot activation signal are non-real, then estimate an interference result in yard border based on described first signal or described secondary signal based on described channel estimation result;
When particular frame activation signal and special pilot activation signal are true time, then estimate described code border based on special pilot frequency-region signal and described channel estimating result and disturb result;
Described secondary signal or described first signal is upgraded according to described code border interference result;
Estimate between first passage based on described secondary signal or described first signal and based on described channel estimation result and disturb result;
Result is disturbed based on disturbing result and described channel estimation result to estimate between second channel between described first passage based on described secondary signal or described first signal; And
According to disturbing result to upgrade described secondary signal or described first signal between described second channel; And equilibrium treatment is carried out to described first signal, and export described first signal after equilibrium treatment;
Wherein, estimate the step described special pilot frequency-region signal to comprise:
Obtain a special pilot time-domain signal;
One fast fourier transform is carried out to described special pilot time-domain signal, to obtain a First ray signal;
Described First ray signal is carried out to first and second frequency reducing sampling process of 0.5 frequency multiplication, obtain first and second frequency reducing sampling sequence signal respectively to obtain, wherein said first and second frequency reducing sampling process system obtains multiple odd point of described First ray signal and multiple signal values of even number point respectively;
One first-phase displacement process, one first low-pass filtering treatment and a second-phase displacement process are sequentially carried out to first and second frequency reducing sampling sequence signal described, to produce the one second and the 3rd sequence signal respectively;
One zero padding interpolation processing is carried out to described First ray signal, to produce one the 4th sequence signal;
Described first to fourth sequence signal is chosen as one the 5th sequence signal according to described echo mode signal and a fast fourier transform mode signal; And
Carry out after a third phase displacement process, one second low-pass filtering treatment, one the 4th phase shift process to be multiplied with a norm and to process, described special pilot frequency-region signal to estimate to described 5th sequence signal in order.
2. the processing method of quadrature carrier frequency division multiplexed signals according to claim 1, it is characterized in that, echo processing after if echo mode signal indication adopts, then equilibrium and decision-making treatment are carried out to described first signal, with produce balanced with decision-making after described first signal and obtain described special pilot frequency-region signal; When particular frame activation signal or special pilot activation signal are non-real, estimate described code border based on described first signal after balanced and decision-making and described channel estimating result and disturb result.
3. the processing method of quadrature carrier frequency division multiplexed signals according to claim 2, is characterized in that, wherein, described secondary signal is updated to described secondary signal deduct described code border interference result subtract each other result.
4. the processing method of quadrature carrier frequency division multiplexed signals according to claim 3, it is characterized in that, wherein, after described equilibrium and decision-making treatment are carried out to described secondary signal, produce between described first passage based on the described secondary signal after balanced and decision-making and described channel estimating result and disturb result.
5. the processing method of quadrature carrier frequency division multiplexed signals according to claim 4, it is characterized in that, wherein, results added is disturbed to by between described secondary signal and described first passage, and described equilibrium and decision-making treatment are carried out to addition result, estimate between described second channel according to the described addition result after balanced and decision-making and described channel estimation result and disturb result.
6. the processing method of quadrature carrier frequency division multiplexed signals according to claim 5, is characterized in that, wherein, described secondary signal is deducted between described second channel and disturbs result, and described secondary signal is updated to and subtracts each other result.
7. the processing method of quadrature carrier frequency division multiplexed signals according to claim 1, it is characterized in that, if echo mode signal indication adopts pre-echo process, then equilibrium and decision-making treatment are carried out to described secondary signal, with produce balanced with decision-making after described secondary signal and obtain described special pilot frequency-region signal; When particular frame activation signal or special pilot activation signal are non-real, estimate described code border based on the described secondary signal after balanced and decision-making and described channel estimating result and disturb result.
8. the processing method of quadrature carrier frequency division multiplexed signals according to claim 7, is characterized in that, wherein, by described first signal update be described first signal deduct described code border interference result subtract each other result.
9. the processing method of quadrature carrier frequency division multiplexed signals according to claim 8, it is characterized in that, wherein, after described equilibrium and decision-making treatment are carried out to described first signal, produce between described first passage based on described first signal after balanced and decision-making and described channel estimating result and disturb result, and by described first signal update be described first signal deduct to disturb result between described first passage subtract each other result.
10. the processing method of quadrature carrier frequency division multiplexed signals according to claim 9, it is characterized in that, wherein, carry out described equilibrium and decision-making treatment to by described first signal, estimate between described second channel according to described first signal after balanced and decision-making and described channel estimating result and disturb result.
The processing method of 11. quadrature carrier frequency division multiplexed signalss according to claim 10, it is characterized in that, wherein, be that described first signal deducts and disturbs result between described first passage and add the result of calculation disturbing result between described second channel by described first signal update.
The processing method of 12. quadrature carrier frequency division multiplexed signalss according to claim 1, it is characterized in that, wherein, the processing method of described quadrature carrier frequency division multiplexed signals is used in a receiver of a second generation ground system of digital television broadcast, described special pilot frequency-region signal is a P1 pilot tone frequency-region signal, and described first to the length of described 4th sequence signal be respectively 2048 points, 1024 points, 1024 be greater than 2048 points.
The processing method of 13. quadrature carrier frequency division multiplexed signalss according to claim 12, it is characterized in that, wherein, one first to fourth special angle corresponding to described first to described 4th phase shift process is 2 π (512/N), 2 π (-512/N), 2 π (1024/N) and 2 π (1024/N), wherein, N is 2048.
The processing method of 14. quadrature carrier frequency division multiplexed signalss according to claim 12, it is characterized in that, wherein, when described fast fourier transform mode signal represents that the length of the inverse fast fourier transform that described second generation ground system of digital television broadcast uses is 1024 points, and described echo mode signal indication answers the process of described employing pre-echo, then select described second sequence signal as described 5th sequence signal; When described fast fourier transform mode signal represents that the length of the described inverse fast fourier transform that described second generation ground system of digital television broadcast uses is 1024 points, and described echo mode signal indication should echo processing after described employing, then select described 3rd sequence signal as described 5th sequence signal; The length representing the described inverse fast fourier transform that described second generation ground system of digital television broadcast uses when described fast fourier transform mode signal is 2048 points, then select described First ray signal as described 5th sequence signal; When described fast fourier transform mode signal represents that the length of the described inverse fast fourier transform that described second generation ground system of digital television broadcast uses is for being greater than 2048 points, then select described 4th sequence signal as described 5th sequence signal.
The estimating and measuring method of 15. 1 kinds of special pilot frequency-region signals, a special pilot frequency-region signal for estimating, it is characterized in that, the estimating and measuring method of described special pilot frequency-region signal comprises:
Obtain a special pilot time-domain signal;
One fast fourier transform is carried out to described special pilot time-domain signal, to obtain a First ray signal;
Described First ray signal is carried out to first and second frequency reducing sampling process of 0.5 frequency multiplication, first and second frequency reducing sampling sequence signal is obtained respectively to obtain, wherein, described first and second frequency reducing sampling process system obtains multiple odd point of described First ray signal and multiple signal values of even number point respectively;
One first-phase displacement process, one first low-pass filtering treatment and a second-phase displacement process are sequentially carried out to first and second frequency reducing sampling sequence signal described, to produce the one second and the 3rd sequence signal respectively;
One zero padding interpolation processing is carried out to described First ray signal, to produce one the 4th sequence signal;
Described first to fourth sequence signal is chosen as one the 5th sequence signal according to described echo mode signal and a fast fourier transform mode signal; And
Carry out after a third phase displacement process, one second low-pass filtering treatment, one the 4th phase shift process to be multiplied with a norm and to process, described special pilot frequency-region signal to estimate to described 5th sequence signal in order.
The estimating and measuring method of 16. special pilot frequency-region signals according to claim 15, it is characterized in that, wherein, the estimating and measuring method of described special pilot frequency-region signal is used in a receiver of a second generation ground system of digital television broadcast, described special pilot frequency-region signal is a P1 pilot tone frequency-region signal, and described first to the length of described 4th sequence signal be respectively 2048 points, 1024 points, 1024 be greater than 2048 points.
The estimating and measuring method of 17. special pilot frequency-region signals according to claim 16, it is characterized in that, wherein, one first to fourth special angle corresponding to described first to described 4th phase shift process is 2 π (512/N), 2 π (-512/N), 2 π (1024/N) and 2 π (1024/N), wherein, N is 2048.
The estimating and measuring method of 18. special pilot frequency-region signals according to claim 16, it is characterized in that, wherein, when described fast fourier transform mode signal represents that the length of the inverse fast fourier transform that described second generation ground system of digital television broadcast uses is 1024 points, and described echo mode signal indication answers the process of described employing pre-echo, then select described second sequence signal as described 5th sequence signal; When described fast fourier transform mode signal represents that the length of the described inverse fast fourier transform that described second generation ground system of digital television broadcast uses is 1024 points, and described echo mode signal indication should echo processing after described employing, then select described 3rd sequence signal as described 5th sequence signal; The length representing the described inverse fast fourier transform that described second generation ground system of digital television broadcast uses when described fast fourier transform mode signal is 2048 points, then select described First ray signal as described 5th sequence signal; When described fast fourier transform mode signal represents that the length of the described inverse fast fourier transform that described second generation ground system of digital television broadcast uses is for being greater than 2048 points, then select described 4th sequence signal as described 5th sequence signal.
The estimating apparatus of 19. 1 kinds of special pilot frequency-region signals, a special pilot frequency-region signal for estimating, it is characterized in that, the estimating apparatus of described special pilot frequency-region signal comprises:
One fast fourier transformer, for obtaining a special pilot time-domain signal, carries out a fast fourier transform to described special pilot time-domain signal, to obtain a First ray signal;
One sequence signal generator, fast fourier transformer described in electric property coupling, for carrying out first and second frequency reducing sampling process of 0.5 frequency multiplication to described First ray signal, first and second frequency reducing sampling sequence signal is obtained respectively to obtain, one first-phase displacement process is sequentially carried out to first and second frequency reducing sampling sequence signal described, one first low-pass filtering treatment and a second-phase displacement process, to produce the one second and the 3rd sequence signal respectively, one zero padding interpolation processing is carried out to described First ray signal, to produce one the 4th sequence signal, and choose described first to fourth sequence signal as one the 5th sequence signal according to described echo mode signal and a fast fourier transform mode signal, wherein, described first and second frequency reducing sampling process obtains multiple odd point of described First ray signal and multiple signal values of even number point respectively, and
One special pilot frequency-region signal generator, sequence signal generator described in electric property coupling, for carrying out after a third phase displacement process, one second low-pass filtering treatment, one the 4th phase shift process to be multiplied with a norm and to process, described special pilot frequency-region signal to estimate to described 5th sequence signal in order.
The estimating apparatus of 20. special pilot frequency-region signals according to claim 19, it is characterized in that, wherein, the estimating apparatus of described special pilot frequency-region signal is used in a receiver of a second generation ground system of digital television broadcast, described special pilot frequency-region signal is a P1 pilot tone frequency-region signal, and described first to the length of described 4th sequence signal be respectively 2048 points, 1024 points, 1024 be greater than 2048 points.
The estimating apparatus of 21. special pilot frequency-region signals according to claim 20, it is characterized in that, wherein, one first to fourth special angle corresponding to described first to described 4th phase shift process is 2 π (512/N), 2 π (-512/N), 2 π (1024/N) and 2 π (1024/N), wherein, N is 2048.
The estimating apparatus of 22. special pilot frequency-region signals according to claim 20, it is characterized in that, wherein, when described fast fourier transform mode signal represents that the length of the inverse fast fourier transform that described second generation ground system of digital television broadcast uses is 1024 points, and described echo mode signal indication answers the process of described employing pre-echo, then select described second sequence signal as described 5th sequence signal; When described fast fourier transform mode signal represents that the length of the described inverse fast fourier transform that described second generation ground system of digital television broadcast uses is 1024 points, and described echo mode signal indication should echo processing after described employing, then select described 3rd sequence signal as described 5th sequence signal; The length representing the described inverse fast fourier transform that described second generation ground system of digital television broadcast uses when described fast fourier transform mode signal is 2048 points, then select described First ray signal as described 5th sequence signal; When described fast fourier transform mode signal represents that the length of the described inverse fast fourier transform that described second generation ground system of digital television broadcast uses is for being greater than 2048 points, then select described 4th sequence signal as described 5th sequence signal.
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CN110445738A (en) * | 2019-07-12 | 2019-11-12 | 四川安迪科技实业有限公司 | A kind of phase estimation method and device based on scattered pilot auxiliary |
CN114978816A (en) * | 2021-02-26 | 2022-08-30 | 瑞昱半导体股份有限公司 | Channel estimation method |
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