Research On The Channel Estimation For SC_FDE Systems In Low SNR Environment

Single-carrier frequency domain equalization technology have drawn much attention in recent years because of it's excellent performance in resisting frequency selective fading.For the technology combined with other techniques,like MIMO,are reported occasionally.While,in the SC-FDE system,the accurate channel estimation result is very important to the system performance.So the focus of this article is about the channel estimation,including the introduction to the characteristics of the wireless channel,a new proposed method of channel estimation in the SC-FDE system which used the Hadamard quadrature modulation and MIMO.In this paper,the main work and innovation points are as the follows.(1)Brief introduction of the characteristics of wireless channel,and the advantages and disadvantages of the SC-FDE system.(2)Channel estimation based on pilot is introduced in detail,including the selection of pilot sequence,the insertion way of pilot sequence and the design of the frame structure.The Golay sequence which has great autocorrelation properties has been used in our communication system.(3)This paper proposed two channel estimation methods which cleverly used the known sequency in Hadamard matrix.Those new method don't need additional pilot sequence and channel estimation operation is very simple and the channel estimation result is also very accurate.(4)We also gived the troposcatter channel test plan including the calculation of the multipath number,the Doppler frequency and the troposcatter channel loss based on the collected data.