多速率信號(hào)處理的設(shè)計(jì)與實(shí)現(xiàn)（Design and implementation of multirate signal processing）

1、多速率信號(hào)處理的設(shè)計(jì)與實(shí)現(xiàn)Design and implementation of multirate signal processingThis paper makes a great contribution to Weihai mountain in ShandongPdf documents may experience poor browsing on the WAP side. It is recommended that you select TXT first or download the source file to the local machine.Sixth phas

2、e of experimental science and technology in December 2006Experimental garden for College StudentsThreeDesign and implementation of multirate signal processingChen Yiou, Li GuangjunUniversity of Electronic Science and technology of China, Chengdu, 610054Thirty-threeAbstract: the multi rate signal pro

3、cessing is the basic theory of software radio, this paper introduces an efficient processing method of multi rate signal, which uses C IC filter and HB filter, F IR filter and polyphase filters for decimation and interpolation in order to achieve the purpose of changing the signal rate. This paper i

4、ntroduces the basic principle of various filters, analyzes the problems needing attention in the design and implementation, and gives the design results of digital down conversion with this multirate signal processing method. Keywords: multi rate signal processing; C IC filter; HB filter; decimation

5、; interpolation; polyphase filtering in the graph classification number: TN92 document identification code: A article number: 1672-4550 (2006) 06 - 0113 - 04D esign and Rea Liza tion of M ulti - Ra te S igna L Processi g n(University of Electronic Science and Technology of China Chengdu Abstract: M

6、ulti 610054) - Rate signal p rocessing is a basic theory in softw a re rad io. This paper introduces a m ethod of multi - rate signal p rocessing which uses C IC filters, HB filters, F I filters and polyphase fil2 R of using this technique to design a digital down converter ters reach the goal. To o

7、f decim ation and interpolation, in order to change the rate of digital signals It in2 troduces the structures of the. Typ ical filters, analyzes some relevant issues, and brings forward the result Key words: multi - rate signal p rocessing; C I filter; HB filter deci; ate; interpolate; polyphase C

8、m CHEN Yi2, L I Guang2jun ouC IC1 IntroductionMake spectrum worse. Therefore, the essence of multirate signal processing is to cooperate with several typical filters through decimation and interpolation in time domain so as to achieve the purpose of signal rate conversion. A typical multirate signal

9、 processing architecture is shown in figure 1. Filter n.HB extractionMulti rate signal processing is the basic theory of software radio system, it through the interpolation and extraction rate of change of the digital signal in software radio system to adapt to the different modules of the signal to

10、 the different rates of 1 - 2, is an important technology for digital down conversion and digital frequency. In practical engineering, in order to change the rate of digital signals and avoid signal frequency aliasing, usually adopt the following filter: C IC decimation filter, HB filter 2 times ext

11、raction or within the multiphase structure of F filter and IR filter.Wave filterFilter n.F IRPolyphase filter bankFilter n.HB interpolationFig. 1 a typical multirate signal processing architectureAlgorithm and implementation of more than 2 rate signal processingBecause the C IC filter is simple in s

12、tructure and high in frequency, it is used in the first stage of high speed digital signal processing. After its integer multiple decimation,The rate of high-speed signals is greatly reduced. HB decimation filter computation than the general F IR filter small half, processing rate is higher, but bec

13、ause each filtersection only 2 times the extraction, so using HB filters N cascade of signalsThe basis of multirate signal processing is decimation and interpolation, which can be directly extracted and interpolated in time domain, which leads to the expansion and compression of the frequency domain

14、,Thirty-threeThreeePub 2006 - 08 - 02author Chen Yiou (1982 -), female, graduate student, the main research direction is digital signal processing and ASIC design.- 113-December 2006 Experim ent Science & Technology Sixth2 times decimation. Since the C IC filter and the HB filter are all aliasing fi

15、lters, the signal needs to be filtered by the F IR filter to eliminate the unwanted frequency components, and then the next step is to be processed. The polyphase filter banks can convert the fractional sampling rate, make the rate conversion more flexible, and also make the output speed of the whol

16、e system meet the needs of special applications. After the polyphase filter bank, the cascaded HB interpolation filter can also be used to improve the time resolution of the output signal. Next, the algorithm of each filter and the problems to be noticed in the design and implementation are introduc

17、ed in detail. 211 integral comb filter (C IC filter) C IC filter is composed of integrator H1 (z) and comb filter: Omega D, Omega, omega (1 - D) /2 J -1 J) x a () x E H (E = D * a (S S 22), where D is a decimation factor. Because the sidelobe level of single-stage C IC filter is only higher than tha

18、t of the main lobe levelH2 (z) is cascaded, and its frequency response is3NBandwidth of non aliasing signal in decimation. In this case, the signal bandwidth can be improved by first interpolating the data and then using the C IC filter to extract the signal bandwidth. According to the correlation f

19、ormula, there are two ways to increase the bandwidth of non aliasing signal under certain stopband attenuation. One is to reduce the decimation factor D, and the other is to improve the sampling rate. 212 half band filter (HB filter)Graph 210 order HB filterHB filter is a special kind of F I low pas

20、s filter, blanking RIn addition to zero at zero, the excitation response is zero at the other even points. Compared with the conventional F IR filter, it requires only half the amount of computation, and can handle higher speed data. Therefore, HB filter is especially suitable for dealing with decim

21、ation or interpolation of 2 times rate. According to the HB filter coefficients and the properties of decimation or interpolation, the general structure of F IR filters is simplified. Taking the 10 order HB filter as an example, the simplified HB decimation filter and the HB interpolation filter are

22、 shown in Figure 2 (a) and Figure 2 (b), respectively. It is worth noting that the HB filter is also a aliasing filter, and after filtering, aliasing occurs in the frequency domain. Therefore, the passband must be carefully designed and the output of the HB filter will be fully modulated by the F IR

23、 filter.Small 13146 dB, stopband attenuation is very poor, it will cause serious aliasing, it is difficult to meet the practical requirements. Therefore, multilevel cascaded C IC filters are often used in engineering. In the specific implementation, we should pay attention to the following questions

24、 4. 21111 processing gainThe processing gain of Q cascaded C IC filter is DQWith the increase of Q and increase the series extraction factor D, processing gain becomes larger, so the realization of C IC filter, can be inserted into a barrel at the end of the input shape shifter to adjust the gain, t

25、o ensure that each class has enough precision, and output to full output.The 21112 phase nonlinear PI C IC filter in 0 2 of the interval is not completely linear PI, every 2 /D will produce a phase jump, but in each PI interval is 2 /D interval, it is a linear phase. Since the useful signal of PI li

26、es in its linear phase region (02 /D), the signals in the rest of the range must be suppressed, so the nonlinear phase has no effect on the filtering and the extracted results. In view of the effect, the C IC filter is still a linear phase filter. 21113 stopband attenuation of PI in the main lobe ne

27、ar 2 /D digital frequency, attenuation than the much larger attenuation in the first sidelobe peak point filter, PI is close to the 2 /D, the greater the attenuation, as long as the attenuation value of PI is large enough at this frequency, when the signal bandwidth is less than (be selected /D - 2,

28、 omega) to generate the signal bandwidth from the aliasing can be neglected. 21114 improve the aliasing free bandwidth in some application environments, the sampling rate is higher than the back-endHB filter and F IR filter can handle the highest rate, while theThe fractional multiplication of sampl

29、ing rate can be achieved by I interpolation 5 and then D times extraction. Before the interpolation is inserted, the baseband spectrum width of the intermediate sequence is not less than the baseband spectrum width of the original input sequence spectrum or the output sequence spectrum, otherwise it

30、 will cause the signal distortion. A polyphase interpolation filter with 192 orders and 32 phases is taken as an example. As shown in Fig. 3, the 192 order filter is in accordance with every other orderThe signal bandwidth is greater than C IC filter with the minimum stopband attenuation of 114-More

31、 than 213 phase filterSixth phase of experimental science and technology in December 2006The principle of 31 taps as a group was divided into 32 groups, 6 in each groupTap. Each set of corresponding taps is delayed by one clock cycle, i.e., the external inputs are sent to the 32 group. For each grou

32、p, the inputs corresponding to the 6 taps are multiplied by the tap factor of 31 taps apart, and the rest of the inputs are multiplied by 0. In this way, each group has been interpolated 32 times. When the output is controlled, the toggle switch is rotated at different speeds to realize the extracti

33、on of different rates, and the purpose of fractional rate conversion is achieved.Figure 4 N order F IR filter using DA algorithmImplementation of 3 algorithmMulti rate signal processing is the basic theory of software radio, and digital down conversion is one of the keys to software radio. The autho

34、r uses the multi rate signal processing method for a high performance digital down conversion circuit is implemented on the A ltera FPGA Stratix S40, and designed the demodulation module, automatic gain module and coordinate conversion module, its performance has reached the most widely used digital

35、 down conversion chip: Intersil 50214B the level of. The integrated tool Quartus II 510 gives a comprehensive report on the DDC design as shown in Figure 5 (a): a total of 31401 basic logic units are used. The key path shown in Figure 5 (b) shows that the circuit can work stably at a clock frequency

36、 of 80 MHz even if the 30% margin is retained. Figure 6 is using the simulation software ModelSim to design6Implementation of phase decimation filter in figure more than 3The waveform obtained by simulation is consistent with the result of M atlab simulation, which proves the design is correct.In th

37、e frequency domain, the filtering effect is very unsatisfactory, so the F IR filter must be filtered to eliminate the redundant frequency components before the post processing. There are two choices for the implementation of F IR filters: one is the traditional multiply add structure, but the other

38、is the traditional multiplication and addition structure,When the order of the filter is high, the circuit runs very slowly, and the resource consumption is amazing. The other is using DA algorithm (distributed algorithm). The essence of DA algorithm is a look-up table method. It changes the order o

39、f the operations, calculates all possible products before work, saves them in the table, and looks up the tables at work. The F IR filter structure using the DA algorithm is shown in figure 4.The processing speed of DA algorithm only depends on the data width of input signalFor large scale product s

40、um operations, the computation speed has obvious advantages. When the data width of the input signal is too large, the data will be transferredDA algorithm is improved to parallel string structure, which can get faster processing speedDegree. The lookup table used in DA algorithm should be stored in

41、 SRAM.214 F IR filterBecause the C IC filter and the HB filter are aliasing filteringFigure 5 example of Quartus design- 115-December 2006 Experim ent Science & Technology SixthReference1 Li Shixin, Liu Luyuan 1 Research on wavelet domain median filter design 2 Ma said, Zhang Xiangguang, Yang Miao 1

42、 multi structure element based on generalized morphological filter 3 Yang Xiaoniu, Lou Cai Yi, Xu Jianliang 1 software radio principle and application 4 Chen Yong 1 FPGA high speed dedicated DDC D 1 5 6 1 Qin Honggen, based on Pan Ganghua, Mei Jianping think 1 laboratory construction should follow t

43、he sustainable 2 has jumped 1 on Higher Vocational Education J 1 China quality education theory 3 Dong Jiashou, Zhang Wengui 1 of the laboratory construction and management J1 M 1 University of Electronic Science and technology 2003, 32 (1): 18 - 211 Intersil - 831 Inc1 HSP50214BFigure 6 ModelSim si

44、mulation waveform4 ConclusionThis paper studies the implementation of multirate signal processing, that is, using C IC filter, HB filter, F IR filter and polyphase filter and other typical filters to achieve signal extraction and interpolation. This paper introduces the basic principle of the algori

45、thm, and analyzes the important problems which should be paid attention to in the design and implementation. The digital down conversion realized by the multi rate signal processing method has successfully passed the FPGA verification.(up to fifty-eighth pages)Ping, improve the ability of scientific

46、 research and development, out of a new way to train double qualified teachers. This has laid a solid foundation for further development of training bases and improving the level of practical teaching, speeding up the transformation of scientific research resources into educational resources.The new

47、 platform, the theory relating to teaching, course design and graduation design on this platform, including the integrated substation automation, railway signals, railway engineering machinery detection, vehicle detection and maintenance, the train scheduling sub project of electrified railway tract

48、ion, good training environment for training iron talents, part of the sub project has started construction.5 training base expansion and improvement ideasAccording to the current situation of talent demand, the focus of personnel training in domestic transportation Colleges (including the Railway Co

49、llege) has shifted, which has weakened the cultivation of the original railway talents. However, with the continuous development of the countrys western development, infrastructure construction has been rapid development, Metro, light rail construction has begun operation in some large cities. All o

50、f these require a great deal of expertise in modern railway knowledge. Therefore, Emei Campus Based on its own characteristics, for the railway development, and actively adjust the direction of personnel training, invite the units involved in the development of plan of personnel training, running th

51、e main professional focus on the needs of setting and updating of the railway, with the railway engineering characteristics focus on training practical talents. According to the school laboratory investment plan,Southwest Jiao Tong University launched the 323 Engineering Laboratory (process that is

52、2 to 3 years, investment of about 200 million yuan of funds, focusing on the construction of 20 30 based laboratory and transformation of 20 specialized laboratories), Emei campus actively seize the opportunity, based on the existing training base, apply with characteristics of railway engineering p

53、ractice the training base construction project, as the original innovation of teaching content and teaching methods.6 concluding remarksTraining base, as an important place of practice in Colleges and universities, is the key link of transforming students theoretical knowledge into practical skills,

54、 and also fully embodies the level, quality and characteristics of University running. Therefore, it is an important task for universities to build a good training base with distinctive characteristics, which is of great importance to the cultivation of highly skilled and practical talents. Referenc

55、eTo read all good books is to speak to many noble men.- 116-All: University of Electronic Science and technology of China, 2005: 10-441, Beijing: Tsinghua University press, 20031 and practice, 2003, 9 (1): 2631: University of Electronic Science and Technology Press, 20041Www1 Intersil1 com, 1995 - 0

56、5 - 011Improved algorithm of wave J 1 Journal of University of Electronic Science and technology of China, 2004, 33 (4):391-3941 M 1 Beijing: Publishing House of electronics industry, 20011The road of development J 1 laboratory research and exploration, 2004, 5 (23): 82Uwe implementation of FPGA M E

57、yer - Baese1 digital signal processing M 1- DescartesDatasheet DB /OL 11. This paper makes great contributions to Weihai mountain in ShandongPdf documents may experience poor browsing on the WAP side. It is recommended that you select TXT first or download the source file to the local machine.Sixth

58、phase of experimental science and technology in December 2006Experimental garden for College StudentsThreeDesign and implementation of multirate signal processingChen Yiou, Li GuangjunUniversity of Electronic Science and technology of China, Chengdu, 610054Thirty-threeAbstract: the multi rate signal processing is the basic theory of software radio, this paper intr