Efficient Multiple Access Schemes for Next Generation Wireless Communications

Abstract

Since the resources (such as time, frequency and code) in wireless networks are usually limited, it is critical for wireless network designers to utilize these resources efficiently and effectively. Multicarrier modulation and spread spectrum schemes like OFDM, OFDMA, MC-CDMA, MC-DS-CDMA and DS-CDMA are known to provide high spectral efficiency. However, the future demands on high data rate and mobility require the design of new air interfaces for next generation of mobile radio systems with even higher spectral and system efficiency, flexibility in data rates and robustness. We try to address some of these issues in this thesis by proposing four efficient multiple access schemes.