一种MIMO-OFDM视频传输系统信道估计的实现

An Implementation of Channel Estimation Based on MIMO-OFDM Video Transmission System

摘要: 正交频分复用(OFDM)系统因为其频谱利用率高、多径传输性能好的优点，得到了研究者们的极大关注。结合多输入多输出(MIMO)技术的OFDM系统更是以其传输可靠性高，速度快，已经成为了第四代无线通信技术的关键。为了支持基于MIMO-OFDM的高清视频双向传输系统进行无线传输，需要在接收链路中设计一种信道估计方案来对抗多径传输带来的频率选择性衰落。本文提出了一种基于参考信号的信道估计的FPGA实现方案。该方案采用最小二乘算法(LS)在频域进行参考信号位置信道估计，通过时域频域二维线性插值算法得到用户数据位置信道参数，并利用二叉树流水线技术及AXI-Steam总线协议进行模块化设计，结构优化。经测试，该方案占用FPGA资源少，并且能够在实验室环境下有效抵抗信道衰落。

Abstract: Because of its advantage of spectrum effectiveness and multi-path transmission, orthogonal fre-quency division multiplexing (OFDM) system gains extensive attention. OFDM technology com-bining with MIMO technology which can be faster and more reliable has become the key of fourth generation wireless communication. In order to support MIMO-OFDM system to conduct wireless real-time transmission of high-definition video, a channel estimation scheme is needed in receiver to overcome frequency selective fading. In this paper, the channel estimation scheme applies least square algorithm to estimate the channel parameter on reference signal position, and adopts two- dimensional linear interpolation algorithm to estimate the channel parameter on user data position. The scheme is implemented and optimized by pipeline architecture of binary tree and Advanced Extensible Interface. According to test, this scheme occupies less FPGA resources, and is able to overcome channel fading in laboratory environment.