Basic Studies on High Bit-rate Indoor Wireless Local Area Network

本研究在分析城市移动无线电多径传播研究的基础上，从理论上和实验上研究了室内多径传播结构的特征、调制技术和局域网的组成技术，以实现高比特率的局域无线网络。得到的结果如下：测量了400 MHz频段的多径传播特性和误码率性能，为室内无线电系统的设计提供了有价值的数据。并对1.5 GHz频段的功率延迟曲线进行了测量，分析了产生延迟的原因，得到了简单的延迟估计方法。提出了BPSK在役多径时延扩展测量方法，并对其在分集支路选择策略中的应用进行了研究。此方法稍作修改，也适用于QPSK。通过城市和大学校园的现场测试结果，对PSK-RZ抗多径调制方案进行了实验研究，揭示了微小区无线电区系统的基本性能。采用自适应变包长假设和混合ARQ纠错控制对分组无线电系统的吞吐量进行了研究。利用数字信号处理技术，研究了一种实现局域无线网络所需的简单无线电收发器，该收发器可通过lsis实现。详细研究了viterbi自适应均衡器在各种调制方案下的性能，提出了一种利用定向天线组合分集接收系统的新指标，其性能优于后均衡器选择分集接收系统。

In this research, we have studied on the characterization of indoor multipath propagation structure, modulation techniques, and component techniques of LAN, theoretically and experimentally to realize a high bit-rate local area radio network, based on our experiences in the analysis of multipath propagation studies in urban mobile radio. Followings are obtained results.1. Multipath propagation characteristics and bit error rate performance were measured at 400 MHz band, which gives valuable designing data for indoor radio system. And power delay profile measurements were done at 1.5 GHz band to analyze the causes of delay, resulting in simple delay estimation method.2. In-service multipath delay spread measurement method were invented for BPSK and studied on its application for the diversity branch selection strategies. This method also applicable for QPSK by a slight modification.3. Anti-multipath modulation scheme PSK-RZ were experimentally studied by field tests results in urban areas and in university campus, which reveals basic performance in micro-cell radio zone system.4. The throughput of packet radio systems were studied by assuming adaptive variable packet length and hybrid ARQ error correcting control on fading channels.5. A simple radio transceiver necessary for the realization of local area radio network was studied by using digital signal processing, which is realizable by LSIs.6. The performance of viterbi adaptive equalizer were studied in details for various modulation schemes and a new metrics combining diversity reception system utilizing directional antennas was proposed, which shows better performance than post-equalizer selection diversity reception system.