1、 院 部 _ 专业班级 _ 届 次 学生姓名 学 号 指导教师 二一一 年 六 月 十 日装订线. . . 7Introduction to Digital Signal Processing Signal and digital signal processing as a branch of information processing, has infiltrated into the scientific research, technological development, industrial production, national defense and national e
2、conomy in various fields has achieved fruitful results. Of the signal in time domain and transform domain analysis of the characteristics, processing, enable us to the nature of the signal features and a more clear awareness and understanding of the signals need to get our form of information of use
3、 to improve the extent, then in a broader and higher level the access to information. DSP chip, also known as digital signal processors, is particularly suitable for digital signal processing microprocessor. The emergence and development of DSP chips, digital signal processing technology for the imp
4、rovement of many of the new system, the new algorithm came into being, the application field is expanding. Currently, DSP chips have been widely used in communications, automation, aerospace, military, medical and other fields. Digital signal processing is that the signal to digital form and deal wi
5、th the theory and technology. Digital signal processing and analog signal processing is a subset of signal processing. The purpose of digital signal processing is a continuous real-world analog signals to measure or filter. Therefore needed before carrying out digital signal processing the signal fr
6、om the analog domain into the digital domain, this is usually achieved through the ADC. The digital signal processing often have to transform the output to the analog domain, which is achieved through the DAC. The core digital signal processing algorithm is the discrete Fourier transform （DFT）, is t
7、he DFT to the signal in the digital domain and frequency domain are realized discrete, general-purpose computer which can handle discrete signal. Er Shi digital signal processing theory to practical from the fast Fourier transform （FFT）, FFT has significantly reduced the DFT computation to make real
8、-time digital signal processing as possible, greatly promote the development of the discipline.The advantages of digital signal processing system as follows: 1. Good flexibility: when the processing method and parameters change, the processing system simply by changing the software design to meet th
9、e appropriate changes. 2. Precision: Signal processing systems can be A / D transformation of the median, the processor word length and the appropriate algorithm to meet the accuracy requirements. 3. Reliability: processing system affected by environmental temperature, humidity, noise and electromag
10、netic interference caused by the less affected. 4. Can be a large-scale integration: With the technological development of semiconductor integrated circuits, digital circuits can be used for very high integration, small size, low power consumption, and good product consistency.1.The development of D
11、SPThe late 70s early 80s, AMIs S2811 chip, Intels 2902 chip, the birth marks the beginning of DSP chips. With the rapid development of semiconductor integrated circuits, high-speed real-time digital signal processing and digital signal processing applications demands the continuous extension of the
12、field, in the 80 years since the beginning of ten years, DSP made epoch-making development. View from the operation speed, MAC （multiply and accumulate） time of 400 ns from 80 down to 40 ns below, data-processing capacity several times. MIPS （million instructions per second） from the early 80s 5MIPS
13、 to the current 40 MIPS or more. Key components within the DSP chip multiplier accounts from the early 80s about 40% of mold Area dropped to less than 5%, on-chip RAM for more than an order of magnitude increase. View from the manufacturing process, the early 80s with 4m of NMOS technology and is no
14、w using sub-micron CMOS technology, DSP chips, pin numbers from the early 80s up to 64 to more than 200 now, so the increase in the number of chip pins increase the flexibility of application, so that all external memory expansion and more convenient communication between processors. And earlier tha
15、n DSP chips, DSP chips now have two floating point and fixed-point data format, floating-point DSP chips for floating-point operations, so computing precision greatly enhanced. DSP chip cost, size, voltage, weight and power consumption earlier DSP chip with a large degree of decline. In the DSP deve
16、lopment system, software and hardware development tools continue to improve. At present some of the chip with the corresponding integrated development environment, which supports breakpoint settings and program memory, data memory and DMA access and the program running and tracking a single departme
17、nt, and can use high-level language programming, some manufacturers and some software development business application software for the DSP to prepare a common subroutine library and various algorithms and various interface program, which makes application development easier, shorten development tim
18、e, thus increasing the efficiency ofGeneral characteristics of DSP chips（1） In a cycle to complete a multiplication and an accumulation.（2）Harvard architecture, program and data space separated, you can also access instructions and data.（3） Chip with fast RAM, typically by an independent data bus si
19、multaneously in two visits.（4） A low cost or no cost recycling and jump hardware support.（5） Fast interrupt handling, and hardware I / O support.（6） With single-cycle operation in a number of hardware address generator.（7） Can perform multiple operations in parallel.（8） To support pipeline operation
20、s, fetch, decode, and execution operations may overlap.2.DSP Applications in Communication System DSP technology has been widely used in communications. Mainly in the following areas. （1）Software Defined Radio Software radio technology and computer technology is constantly touch merged into the 3rd
21、generation mobile communication systems provide a good user interface. DSP hardware technology and its algorithm is the key to realization of software radio. Software radio system flexibility, openness and compatibility features of the signal processor is mainly centered through a common hardware pl
22、atform and software to achieve. It is mainly to complete the internal data processing station, modem and codec and so on. As the internal data flow and a large radio filtering, frequency and other processing operations more often, to high-speed, real-time, parallel digital signal processor module or
23、 ASIC to meet the demand. To complete such an arduous task, to increase the processing speed required hardware, chip capacity expansion and requested algorithm for optimization and improvement of the processor. The two aspects of the continuous improvement requirements will be the development of dig
24、ital signal processing technology unremitting power. The only way to achieve high-speed internal software radio operation and multiple functions of the flexible switching and control. Software implementations are generally two types of devices that use DSP to implement and field-programmable gate ar
25、ray （FPGA） to implement. （2）Speech Coding The purpose of voice data compression is that in the transmission rate as low as possible gain high-quality audio performance, that is, that narrow bandwidth of voice signals Ke Yi in the channel transmission, the voice of quality and Xiajiangdebu more Huo d
26、ropped as much as possible . Speech coding system for the early use of the waveform coding method, also called waveform coding. Essentially follows the Nyquist sampling theorem, strong adaptability, good quality synthetic speech, but the high rate coding, coding efficiency is very low. The parameter
27、 coding is different from the efficient encoding of waveform coding method, which is based on the mechanism in speech production, mainly on the extraction characteristics of speech signal encoding parameters, you can achieve very low encoding rate. But only to the effect of synthesized speech, voice
28、 quality than waveform coding. Over the past decade, speech coding technology has made breakthrough progress. ITU, one after another through a series of low bit rate speech coding standard telephone band. By the parameter coding and waveform coding the hybrid coding method that is of a synthetic cod
29、ing, can get better sound quality at the same time reduce the coding rate, the most representative is the linear predictive coding （LPG） and Code Excited Linear Prediction Coding （CELP）. This encoding can be 4-16kbit / s of the low coding rate on high-quality reconstructed speech, but the complexity
30、 of the algorithm, the computing speed of the processor demanding. On speech processing, the higher the compression ratio, the more complex encoding algorithm, real-time compression can not use the logic circuit, it will not use the bulky, slow, high cost of Microcomputer. The DSP is a suitable choi
31、ce, the web conferencing, voice communications, surveillance systems are important areas of components. The use of DSP voice compression algorithm not only provides a broad application prospects, and the system design simple, reliability is also greatly improved. （3）GPS System GPS was developed by t
32、he United States to receive navigation satellite signals based on non-autonomous navigation system. Is widely used in various military and economic fields. With GPS technology in various fields to promote and popularize the application of the receivers small size, intelligence and algorithms to meet us
