Research Of Single Carrier Frequency Domain Equalization Algorithm

Digital Television Terrestrial Broadcasting technology is one of hot areas in wireless domain. In recent years, various countries are in the research and promotion of digital TV and to be recognized as the next generation of TV systems. China is in the conversion from analogue TV to digital TV, so the development of terrestrial digital television is particularly important. There are three modules influenced the receiver performance, they are decoding, equalization and synchronization. Among them, the channel equalization is particularly important. The role of equalization is to eliminate the effect upon the communication system performance of the multipath fading, doppler effect and additive noise problems in channel of the wireless communication. The single carrier modulation and demodulation technique has been successfully applied to a variety of digital wireless communication systems. Therefore, the research of single-carrier equalization is of great significance.This paper is to study and realize the single-carrier frequency domain equalization algorithm for DTMB digital TV receiver. First analyze the interference and fading characteristic of wireless communication transmission system, discuss the existing single carrier frequency domain equalization algorithm. Through a comparative analysis find that the frequency domain linear equalizer and overlap equalizer can not against deep fading channel influence well, decision feedback equalizer implementation complexity is great. Frequency domain LMS equalization algorithm in the compromise of performance and complexity, and has a strong practical.Analysis of the existing frequency-domain block least mean square equalization algorithm applied exist the slow convergence problem in the system. Introduce the channel estimation algorithms to improve the single-carrier frequency domain's performance. Discussed the channel estimation algorithm respectively, frequency domain estimation method estimates the value of a larger disturbance, but not very accurate; least squares calculation is too large; related comparison algorithm to determine the amount and accuracy of the calculation method of compromise. And propose the variable step algorithm can improve the performance of equalization algorithm.Through MATLAB simulation to verify the feasibility of the algorithm, and simulate the noise factor and the forgetting factor parameters. Completed the C code, and the algorithm is embedded in the DTMB Platform. According to simulate static Brazil channel and dynamic Doppler channel DSE channel, and the simulation results show the improved single-carrier frequency domain equalization algorithm can effectively improve the convergence rate increased about 1/3, and the performance of dynamic channel can improve about ldB.The improved single-carrier frequency domain equalization algorithm can effectively improve the convergence rate, and can reduce the error rate under the same conditions, improved performance of the algorithm to some extent. In addition, the algorithm is also applicable to other similar DTMB transmission system.