The use of multi-antenna technology, also referred to as multiple-input multipleoutput (MIMO), has been shown to improve both the achievable data rates and the link reliability in single-cell wireless systems without a need for extra power or bandwidth. The promised gains of MIMO techniques are, however, severely degraded in a multicell environment due to the presence of intercell interference,...

We consider the downlink of a cellular network with cooperative multiple antenna base stations and single antenna user terminals. Based on a limited number of measured interference channels and an interference prediction strategy, we address the implementation of interference temperatures in a large scale system. With interference temperatures, each base station has linear constraints on its tr...

Mobile broadband communication is experiencing rapid growth in technology, markets and range of services. This rapid growth has driven the recent surge of research and development activities for high-data-rate/high-mobility wireless systems, with improved network performance and enhanced economics. One technology thrust in wireless communications is the use of adaptive antennas at the transceiv...

This paper presents a tested research concept that implements a complex evolutionary algorithm, genetic algorithm (GA), in a multi-microcontroller environment. Parallel Distributed Genetic Algorithm (PDGA) is employed in adaptive beam forming technique to reduce power usage of adaptive antenna at WCDMA base station. Adaptive antenna has dynamic beam that requires more advanced beam forming algo...

We address the problem of performing optimum spatiotemporal processing when using adaptive antenna arrays at base stations for multiuser downlink transmission, assuming the knowledge of the channel related to each user. This assumption typically holds in the context of time division duplex (TDD), time division multiple access (TDMA) based mobile communication systems. For frequency division dup...

NTT DOCOMO Technical Journal Vol. 13 No. 4 ©2012 NTT DOCOMO, INC. Copies of articles may be reproduced only for personal, noncommercial use, provided that the name NTT DOCOMO Technical Journal, the name(s) of the author(s), the title and date of the article appear in the copies. *1 Directivity: One of the radiation characteristics of an antenna. The direction characteristic of the radiation str...

PERFORMANCE IMPROVEMENTS IN WIRELESS CDMA COMMUNICATIONS UTILIZING ADAPTIVE ANTENNA ARRAYS by Weichen Ye This dissertation studies applications of adaptive antenna arrays and spacetime adaptive processing (STAP) in wireless code-division multiple-access (('D11 A) communications. The work addresses three aspects of the CDMA communications problems: (I) near-far resistance, (2) reverse link, (3) ...