【摘要】 为了获得空时协作系统中OFDM调制下的多径增益,提出了一种基于OFDM子载波相关性的空时协作方案.该方案中,在协作的不同阶段,通过变换信号的发送顺序,使同一信号在相关性最小的两个子载波信道上传输,基站将接收到的两阶段信号对应地进行最大比合并.通过对系统中断概率的研究,给出了最佳的功率分配策略,并对系统理论误码率进行了分析.仿真结果表明,该方案可以获得明显的误码率性能增益,在不降低传输速率的情况下,该方案还可获得一阶的多径增益.更多还原

【Abstract】 In order to obtain a multi-path gain of orthogonal frequency division multiplexing(OFDM) in a space-time cooperative system,a space-time cooperative scheme based on the correlation of subcarriers in OFDM is proposed.In this scheme,by changing the order of the same signals in different phases of cooperative transmission,the signals are transmitted in two subcarrier channels with the lowest correlation.Then,corresponding two-phase signals are combined together by the base station via a maximal ratio combing(MRC).Moreover,the outage pro-bability is analyzed,and an optimal power allocation strategy is proposed.Finally,the theoretical bit error rate is analyzed.Simulated results demonstrate that the proposed scheme results in significant gains in bit error rate(BER) performance,and helps to obtain one-order multi-path gains without reducing the transmission rate.更多还原