Multiple access smart antenna systems at both transmitter and receiver for TDD and FDD wireless communications.

摘要

The primary difficulty faced in the development of modern and future wireless communication systems is the shortage of the available radio spectrum. To overcome the spectrum shortage, smart antenna processing (space, space-time) has emerged as a key strategic technology for wireless communication systems due to its inherent potential for significantly improving channel capacity.; An advanced way to increase the channel capacity of a single link is to use smart antennas at both transmitter and receiver. This is more effective because it has been proven theoretically that up to M independent channels can be established in the same bandwidth with M transmitting and M receiving antennas. Using information theory, the channel capacity has also been shown approximately proportional to M (which is more effective than log(M)) if both transmit and receive antenna arrays are used.; In this dissertation, the practical implementation techniques of multiple smart antenna space processing, Pre-processing (SVD approach), Post-processing (MMSE approach), Iterative approach and SVD-MMSE approach for the multiple access wireless communication links at both Time Duplex Division (TDD) and Frequency Duplex Division (FDD) are presented for narrow band channel. Additionally, the autocovariance matrix transmitter processing method where channel estimation technique is employed is suggested and the effects of different moving velocities under the FDD communication link are considered.; For the broadband channel, the lack of channel information on the transmitter side stresses the research of the transmitter, down link (base station to mobile) processing. The novel multiple access space-time processing techniques including the transmitter processing, Pre-processing (GZF approach), Post-processing (MMSE approach) and Hybrid combination of pre-processing and post-processing approach (GZF-MMSE) which suppress the inter symbol interference (IS I) and co-channel interference (CCI) at the same time are presented in TDD and FDD communication links. Also, the performance of linear and non-linear equalizer is compared by simulation. Finally, we propose and analyze the space-time multiple access interference cancellation structure.