On the value of synchronous downlink MIMO-OFDMA systems with linear equalizers

Abstract

Cellular radio systems are often limited due to the presence of cochannel interference. Basically, radio systems may be operated by utilizing asynchronous or synchronous downlink transmission from all base stations in the system, where synchronization between terminals and their serving base station is mandatory in both concepts. We provide a comparison between the theoretical achievable spectral efficiency in an orthogonal frequency division multiple access systems using different linear equalizers and their resulting performance taking estimation errors into account. It is shown, that the choice of the appropriate receiver depends on the degree of synchronization in the system. We demonstrate that a 3G long term evolution radio system may achieve higher spectral efficiency thanks to interference suppression if fully synchronized data transmission from all base stations is introduced.