MIMO-OFDMA时变信道和载波频偏联合估计

Joint Time-varying Channel and Carrier Frequency Offsets Estimation for MIMO-OFDMA Wireless Systems

针对MIMO-OFDMA上行无线通信系统,提出一种基于随机集理论的多用户时变信道和载波频率偏移联合估计算法.该算法基于随机集合理论,利用一个有限随机集合来表示和描述系统中实时动态变化的接入用户状态、多径信道的冲激响应,以及每个无线接入用户对应的载波频率偏移量;然后,利用贝叶斯最优估计理论,给出在随机集模型下MIMO-OFDMA上行无线系统中信道冲激响应和载波频率偏移的最优估计表达式;最后,利用粒子滤波算法逼近求解该随机集模型下的贝叶斯最优估计问题.仿真实验结果表明,在MIMO-OFDMA上行无线系统中接入用户数未知且动态变化等复杂情况下,该算法仍然可以实现对时变信道冲激响应和载波频偏的有效估计.

For the uplink MIMO-OFDMA wireless systems, a joint multi-user channel and cartier frequency offsets （CFOs） estima- tion algorithm is proposed based on the random-set theory. In the algorithm, the states of the active users, the multi-path channels, and the CFOs are described by a finite random set. Then the problem of joint channel and CFOs estimation is thus constructed by the theory of Bayesian optimal estimation, then the optimal estimations of channel and CFOs are obtained and solved by using the particle filtering algorithm. Simulation results show that, the proposed algorithm can effectively estimate the time-varying channel and CFOs, even when the number of active uses is time-varying and unknown in the MIMO-OFDMA uplink systems.