基于RLS的联合同步和信道估计算法

针对采用跳频正交频分复用(frequency hopping orthogonal frequency division multiplexing, FH-OFDM)系统进行战时通信时存在的高误码率(bit error rate, BER)问题，对定时偏差(timing offset, TO)、载波频率偏差（carrier frequency offset, CFO）和采样率偏差(sampling frequency offset, SFO)进行综合考虑，提出一种导频辅助的联合同步和信道估计算法。在时域中分别对TO和子载波干扰项进行预先补偿。使用线性误差函数来配合递归最小二乘法对信道冲激响应、CFO和SFO进行估计。采用改进的极大似然算法对迭代参数的初始值进行估计，提高了估计的准确度。分析并给出FH OFDW系统频谱效率的权衡标准。仿真结果表明，该系统工作在1 000 hop/s时，该算法的估计均方差和BER均优于传统的算法。

Joint synchronization and channel estimation algorithm based on RLS

Considering timing offset(TO),carrier frequency offset(CFO) and sampling frequency offset(SFO) comprehensively in battle field frequency hopping orthogonal frequency division multiplexing(FH-OFDM) application,a pilot-aided joint synchronization and channel estimation algorithm is proposed to improve bit error rate(BER) performance.TO and inter-carrier interference are compensated in time domain.Channel impulse response,CFO and SFO are estimated by a recursive least square algorithm with linear error function.A new maximum likehood algorithm is proposed to estimate parameters’ initial value using in iteration,thus the estimative precision is improved.System balance expression is presented for bandwidth efficiency and hopping rate.Simulation results show that the estimative mean square error and BER performances of the proposed algorithm outperform conventional algorithms under the condition of 1 000 hop/s in FH-OFDM systems.