An introduction to the knowledge of digital signal processors

1. The principle of processing analog signals with digital system: input signal - > preprocessing - > sampling - > quantitative coding - > digital processing system - > digital Hu calendar and analog conversion.

Smooth Filtering - > output signal.

2. The principle of processing analog signals with a time-domain discrete system: input signal - > preprocessing - > sampling (x(n)) - time domain discrete system (y(n)) - recovery filter - > output signal.

The basic theory of deterministic digital signal processing mainly includes the following six points:

1) Preprocessing of analog signals (also known as pre-filtering or pre-filtering): filtering out the useless frequency components and noise in the input analog signal to avoid spectral aliasing distortion after sampling;

2) Time-domain sampling and recovery of analog signals: analog-to-digital conversion technology, sampling theorem.

Quantitative error pants escort search difference analysis, etc.;

3) Analysis of discrete signals and systems in the time domain: signal representation and operation, various transformations (Fourier transform.

z-transform and discrete Fourier transform), time- and frequency-domain description and analysis of discrete signals and systems in the time domain;

4) Fast Algorithms in Digital Signal Processing: Fast Fourier Transform.

Fast convolution. Wait;

5) Analog filter and digital filter analysis, design and bending implementation;

6) Multi-sampling signal processing technology: sampling rate.

The basic principles of the transformation system and the efficient implementation methods.

5. Implementation method of digital signal processing:

Generally, it is divided into software implementation, special hardware implementation, and software and hardware combination implementation.

Principles of communication and digital signal return processing are both basic courses of the major.

In contrast, digital signal processing is more basic, and having studied digital signal processing has some benefits for understanding the principles of communication. Chonghuai hunger.

The basic theoretical requirements of digital signal processing are mainly signals and systems.

The basic theoretical requirements of the principles of communication are mainly information theory.

Signal and system is an analysis method: it is the basis of digital signal processing and communication principles, signal and system mainly describe signal analysis methods and elementary information system characteristic theory, and describe the basic concepts of time domain and frequency domain analysis of signals and systems respectively.

Digital signal processing and communication principles are two professional courses, which are a sublimation course of signals and systems.

Digital signal processing is mainly an extension of signals and systems, which focuses on the explanation of signal processing (filtering) and teaches everyone the concept of filters, which is the most important basic course in the direction of information and signal processing.

The principle of communication makes use of the time-domain frequency domain analysis explained in the signal and system, but the focus is not on signal processing, but on the transmission and reception of the signal, so he does not pay attention to the content of the specific filter, but only pays attention to the performance of the overall communication system, which is the most important basic course in the direction of communication and information system.

In general, signals and systems are analytical. Digital signal processing is an extension of signals and systems, and the core idea remains the same. The principles of communication use digital signal processing and smart signals and systems, but the core idea has changed.

The basic principle is: after the analog signal is collected at a certain frequency, the spring sign is requantized. Get the number letter and guess the loss number. According to the sampling theorem, as long as the sampling frequency is more than twice the frequency of the original analog signal, the analog signal can be recovered from the obtained digital signal.

Summary. The application of digital signal processing in communication refers to the use of digital signal processing technology to realize the function of communication system. Digital signal processing technology can help communication systems improve transmission efficiency, reduce bit error rate, improve channel capacity, enhance signal transmission quality, and can achieve complex signal processing functions.

For example, in wireless communication, digital signal processing technology can be used to implement functions such as diversity, spread spectrum, modulation, demodulation, decoding, noise suppression, and echo cancellation of wireless signals. In addition, digital signal processing can also be used to realize the related functions of multi-access communication, multi-access transmission, multi-access collaboration, multi-access sharing, multi-access collaboration and multi-access cooperation. In short, the application of digital signal processing in communication is an important technology, which can not only improve transmission efficiency, but also realize various complex functions.

The application of digital signal processing in the communication of the dead lease refers to the use of digital signal processing technology to realize the function of the communication system. Digital signal processing technology can help communication systems improve transmission efficiency, reduce bit error rate, improve channel capacity, enhance signal transmission quality, and can achieve complex signal processing functions. For example, in wireless communication, digital signal processing and consolidation techniques can be used to realize functions such as diversity, spread spectrum, modulation, demodulation, decoding, noise suppression, and echo cancellation of wireless signals.

In addition, digital signal processing can also be used to realize the functions of multi-access communication, mega-access transmission, multi-access collaboration, multi-access sharing, multi-access collaboration and multi-access cooperation. In short, the application of digital signal processing in communication is an important technology, which can not only improve transmission efficiency, but also realize various complex functions.

The future development prospects of signal processing technology.

The future development of signal processing technology is very promising. With the continuous development of science and technology, signal processing technology will also be further improved. For example, with the development of computer technology, signal processing technology will be able to achieve more complex functions, thus providing better performance for communication systems.

In addition, with the development of the Internet of Things, 5G communication technology and artificial intelligence technology, the signal processing technology will also be further improved, so that the communication system has more powerful functions. Therefore, the future development prospects of signal processing technology are very broad.

(1) Software realization: pure analog signal processing must be completely realized by hardware, and digital processing can be realized not only by microprocessor, special digital devices, but also by programming. One of the benefits of software enablement is that the processing system can handle large-scale complex processing with a very small footprint.

2) Strong flexibility: analog signal processing system debugging and modification is inconvenient, and the system parameters of digital processing system are generally kept in registers or memory, and it is very simple to modify these parameters to debug the system, especially when the software is implemented. Due to the characteristics of digital devices and software, digital signal processing systems are also very easy to replicate, which is convenient for large-scale production.

3) High reliability: Analog devices are easily affected by electromagnetic waves, ambient temperature and other factors, and the analog signal changes continuously, and the slightest interference is reflected immediately. And the digital device is a logic device, and the digital signal score is represented by the binary representation of "0" and "1", and the interference of a certain range will not cause the change of the digital value, therefore, the anti-interference performance of the digital signal processing system is strong, the reliability is high, and the preservation of data can also be permanently stable.

4) High precision: The data representation accuracy of analog devices is low, and it is difficult to reach more than 10-3, while digital signal processors and digital devices can achieve a word length of 64 bits, and the accuracy of expressing data can reach more than 10-18.

The biggest feature of digital processing should be that a large number of complex processing can be realized with software, such software can run on a computer, can also run on DSP microprocessor, therefore, the size of the system is reduced, reliability, stability is improved, and debugging and changing system functions become convenient. These are the reasons why communication electronic products such as mobile ** are becoming more and more abundant in functions and higher in performance, and the volume is smaller and smaller in meters.

Digital circuits deal with digital signals, binary data, or logic levels.

However, analog-to-digital converters (AD) deal with analog signals, and AD is called an interface circuit, which is generally classified as a digital circuit.

The digital signal is a high and low logic level in the digital circuit inside the machine, and the duration of the high and low levels is uncertain, which is called a pulse signal.

Digital signals are generally transmitted between different systems, and there are many forms of expression: optical signal, amplitude modulation, frequency modulation, phase modulation, current magnitude, etc.

Analog circuits, digital circuits, and hybrid circuits are called signal processing circuits when they process analog signals in block diagrams. Linear amplifier, operational amplifier is a typical analog signal processing device, for small signals, digital circuits such as and gate as long as the working point is set correctly can amplify the analog signal, in the waveform processing is often used gate circuit for waveform conversion, a d, d a conversion device is a typical processing analog signal hybrid circuit.

A digital signal is a signal in which the independent variable is discrete and the dependent variable is also discrete, the independent variable of this signal is represented by an integer, and the dependent variable is represented by a number in a finite number. In computers, the size of a digital signal is often expressed by a binary number with a finite bit, for example, a binary number with a word length of 2 bits can represent 4 sizes of digital signals, which are and 11; If the signal varies in the range of -1 1, then these 4 binary numbers can represent 4 numeric ranges, i.e., [-1, 0), [0, and [, 1].

Since the digital signal is represented by two physical states, 0 and 1, its ability to resist the interference of the material itself and the environment is much stronger than that of the analog signal. In the signal processing of modern technology, digital signals play an increasingly important role, and almost complex signal processing is inseparable from digital signals; In other words, as long as the solution to the problem can be expressed in mathematical formulas, a computer can be used to process digital signals that represent physical quantities.

It deals with strings of 0101, or high and low.