Method for estimating MIMO-SCFDE system channel based on quadrature training sequence

Abstract

The invention provides a method for estimating a MIMO-SCFDE system channel based on an orthogonality training sequence, comprising the following: (1) at a sending terminal, firstly, the orthogonality training sequence is designed according to the number of sending antennas; secondly, the designed training sequence is sent out by each sending antenna according to the designed sequence; (2) the received signal is stored temporarily at each receiving antenna, after all the signals of the training sequence are received, the signals are converted to the frequency domain first; and linear system of equations is solved to obtain the state information on a subchannel in each frequency domain corresponding to the sending antenna and the receiving antenna between each receiving antenna and sending antenna according to the subchannel in each frequency domain; and (3) the received channel state information corresponding to the receiving antenna and the sending antenna is transferred to a time domain to added a window to the time domain channel to remove the influence of noise on the channel guess value, and is transferred to a frequency domain to obtain the channel guess value. The method is suitable to the characteristic of the MIMO-SCFDE system, has low complexity and improves the estimating accuracy of the channel.

Description

technical field [0001] The invention relates to a channel estimation method for a single carrier frequency domain equalization (MIMO-SCFDE) system with multiple transmitting antennas and multiple receiving antennas, and belongs to the technical field of broadband wireless communication. Background technique [0002] Orthogonal Frequency Division Multiplexing (hereinafter referred to as OFDM: Orthogonal Frequency Division Multiplexing) is a multi-carrier transmission technology, which uses N subcarriers to divide the entire wideband channel into N parallel narrowband subchannels that are orthogonal to each other. [0003] OFDM systems have many compelling advantages: [0004] 1. OFDM has very high spectral efficiency. There is no guard interval between sub-channels of OFDM, and the spectrum main lobes of signals in adjacent sub-channels overlap, which greatly improves the spectral efficiency of OFDM systems. [0005] 2. Strong anti-multipath interference ability and anti-fa...

AI Technical Summary

Problems solved by technology

Although MIMO-OFDM and MIMO-SCFDE systems have great similarities, they differ in channel estimation methods: (1) MIMO-OFDM systems generally do not have PAPR requirements for training sequence time domain signals, while for MIMO-OFDM systems The PAPR problem of the time-domain signal of the training sequence of the SCFDE system is often unacceptable to the system; (2) MIMO-OFDM signals generally do not have the PAPR problem in the frequency domain, while the MIMO-SCFDE signal needs to consider the influence of its frequency-domain PAPR problem on channel estimation

Therefore, in general, channel estimation methods for MIMO-OFDM systems cannot be directly used for channel estimation in MIMO-SCFDE systems

[0016] For the MIMO-SCFDE system, there are still relatively few corresponding channel estimation algorithms. After searching the literature of the prior art, it is found that there is only one recursive reconstruction (RR: Recursive Reconstruction) algorithm, which uses a specific training sequence The structure obtains the initial value of part of the channel state information of channel estimation, and then gradually obtains all the channel state information through recursive reconstruction. Although the algorithm only uses one frame of training sequence signal, which improves the utilization rate of bandwidth, the accuracy of channel estimation is not as good as High, especially as the number of transmitting and receiving antennas increases, the accuracy of channel estimation will decrease

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