LTE系统中利用信道估计的天线端口数检测算法

长期演进(LTE）系统中使用多输入多输出(MIMO)技术来改善通信质量并提升信道容量。天线端口数通过循环冗余校验（CRC）掩码的方式隐含于物理广播信道（PBCH）中，遍历1、2、4三种天线端口数情况，分别作为PBCH解码配置，以CRC校验通过并且PBCH解码成功作为确定天线端口数的标志，从而造成冗余计算和时延的产生。为此，提出了一种基于信道估计的天线端口数检测算法，利用正交频分复用（OFDM）调制的LTE信号在空口环境中受频偏和时延影响，造成信道估计结果相位的线性累加，再通过线性回归方程的门限匹配，解决天线端口数检测中频偏影响大、计算量过多和盲检等问题。理论分析和仿真结果表明，该算法复杂度低、时延小，且在残余频偏较大时具有较高的正确率。

An antenna port number detection algorithm based on channel estimation in LTE systems

Multiple-Input Multiple-Output(MIMO) technology is used in Long Term Evolution(LTE) systems to improve communication quality and channel capacity.The number of antenna port is implied in physical broadcast channel(PBCH) by cyclic redundancy check(CRC) mask.Decoding PBCH with the configuration of antenna port number 1,2,4 and taking CRC verification and PBCH decoding success for the flag of antennas detection success results in redundant computing and delay generation.To solve the problem,this paper presents an antenna number detection algorithm based on channel estimation.LTE signals modulated by Orthogonal Frequency Division Multiplexing(OFDM) are affected by frequency offset and delay in the air interface environment,causing the linear accumulation of the phase of the channel estimation result.Then through the linear regression equation of the threshold match,the problem is solved including frequency offset influence,too much calculation and blind processing in antenna port detection.The theoretical analysis and simulation results show that the algorithm has low complexity and low latency,and has high correct rate when the residual frequency is large.