【摘要】 将自适应技术应用于多用户正交频分复用系统,能够提高频谱利用率,降低系统发射功率,从而使系统的整体性能达到最优;针对多用户OFDM系统,将其信道分配和比特分配相结合,提出了更优的多用户OFDM自适应组合调制比特分配算法(M CABA)。根据信道特性的瞬时估计值,自适应地为各用户分配子信道和比特,在给定误码率的条件下使总的发送功率最小,仿真结果表明,该算法计算简单,优化效率高,可以达到接近理论上的最优水平。更多还原

【Abstract】 The application of adaptive technology to the multi-user OFDM system can increase the spectrum usage,reduce the transmission power of the system and optimize the system performance.In this paper we propose a novel multi-user combined-modulation algorithm of adaptive OFDM,which combines the wireless channel and bit allocations.According to the estimation of instantaneous channel characteristics,the adaptive allocation algorithm can assign the sub-channels and bits for each user in the system to minimize the total transmission power with a given bit error rate.Simulated results show that the proposed algorithm is as simple in calculation,high in efficiency and optimal in theory as the optimal scheme.更多还原