Research On Channel Stimation Technique In Fading Multipath Channel Of SC-FDE System With Low SNR

Wideband wireless communication technology has greatly enriched and changed people's daily life,but the frequency selective fading caused by the multipath effect during signal transmission will hazard the reliable and stable of the system.Single-carrier frequency-domain equalization(SC-FDE)technology,can against multipath fading and inter-symbol interference(ISI)with low complexity equalization algorithms.And with low insensitivity to carrier frequency offset and relatively low peak to average power ratio,SC-FDE has wide application and research value in specific fields such as radar communication,underwater acoustic wave communication,and drone communication.This paper mainly studies the SC-FDE system with low SNR and technique used in it,focuses on the channel estimation technique in multipath fading channel.The system uses the channel estimation based on pilot sequence,chosing Go lay Complementary Sequences as PN sequence,and using the LS principle to get the accurate result.Combined with Kalman filter,the existing channel estimation algorithm is improved,and a more accurate SNR estimation result is obtained with high dolpler fading,at the same time the noise estimation also performs better.Kalman filter also is used to process the channel estimation results of each PN sequence when the Doppler fading is low,which makes the channel estimation result more accurate and system performance better.Based on this,an optimized scheme for the frame structure is proposed to reduce the pilot expense without worsening system's performance.Finally,the hardware platform used in the labtorary is modified by the proposed frame structure and algorithm,and by comparing test results with the simulation results,it's proved that themethod works well.The algorithms studied and proposed in this paper have been simulated and verified.The results prove that the channel estimation performance is improved without increasing the hardware complexity,and the BER performance of the system is also optimized to some extent.