一种应用于OFDM系统中的符号精确定时算法的FPGA实现

FPGA-based implementation scheme of accurate timing synchronization algorithm applied to OFDM system

OFDM技术是下一代移动通信的主流技术,在信息量大,功率受限的多媒体传感网的OFDM系统中,以突发模式传输数据,要求快速精确地完成定时同步。这里分析了一种应用于OFDM系统中基于长训练序列与本地序列互相关的精同步算法原理,同时给出了算法的FPGA设计方案,并在ISE中和FPGA测试板上进行验证。在实现的过程中,对传统实现方法进行了改进,对本地序列的位数进行截取符号位处理,并且对判决函数进行了近似处理。实现结果表明,该方法在不降低性能的前提下优化了系统资源损耗和运算速度,具有较好的工程实践价值。

OFDM is the main technology of next generation mobile communication.The data is transmitted in burst-mode,and timing synchronization needs to be fulfilled quickly and precisely in the OFDM system,in which large number of information is transmitted and the power is restricted in multimedia wireless sensor network.The principle of an accurate synchronization algorithm based on cross-correlation between long training sequence and local PN sequence is analyzed.The hardware implementation scheme of FPGA for this algorithm is given,which is verified in the ISE platform and on FPGA test board.The traditional implementation method was modified.The bits of local PN sequence was reduced and an approximate treatment on the decision function was made.This design can effectively reduce the use of hardware resource in the premise of not degra-ding performance,and is convenient for engineering applications.