Study on Cross Layer Optimization Techniques for Mobile Communications

本论文主要研究MIMO-ofdm无线通信，其中MIMO通过多个发射和接收天线对信号进行空间复用，而ofdm代表正交频分复用，即使在多径条件下也能保持良好的传输性能。对于MIMO-ofdm无线通信，我们开发了随机接入技术，通过使用多用户检测(MUD)的信道分配来提高频谱效率。特别是，(1)为各个信号分配不同交织器的交织分复用，(2)通过MUD分离在相同时间和频率上多路复用的分组然后合并重发分组的分组重传方案，等等。

This study focuses on MIMO-OFDM wireless communications in which MIMO spatially multiplexes signals by multiple transmit and receive antennas, and OFDM stands for orthogonal frequency division multiplexing to maintain good transmission performance even under multipath conditions. For the MIMO-OFDM wireless communication, we have developed random access techniques that can improve spectrum efficiency by channel assignment with multiuser detection (MUD). Especially, (1) interleave division multiplexing to assign different interleavers to individual signals, (2) packet retransmission schemes that separate packets multiplexed in the same time and frequencychannel by MUD and then combine retransmitted packets, and so on have been investigated.