【摘要】 针对基于正交频分复用的超宽带系统(OFDM-UWB),提出一种自适应比特分配算法,以对抗超宽带信道的频率选择性衰落.以系统传输速率和均匀功率谱密度为约束条件,将比特分配问题转换为以误比特率(BER)为目标函数的最优化问题,给出了比特分配算法的具体步骤.仿真结果表明该算法可以有效地提高系统性能.更多还原

【Abstract】 To the ultra-wideband systems(OFDM-UWB) based on orthogonal frequency division multiplexing,an adaptive bit allocation algorithm is proposed to combat the frequency selective fading of ultra-wideband channels.Under the constraints of data transmitting rate and uniform power spectrum density,the bit allocation is transformed into an optimization problem,whose target function is bit error rate.The bit allocation algorithm is presented in details.Simulation results suggest that the proposed algorithm can effectively boost the system performance.更多还原