Interference suppression in WCDMA downlink by symbol-level channel equalization

The main air-interface in the 3rd generation cellular communications is wideband CDMA (WCDMA). For WCDMA downlink, multiple access interference (MAI) suppression by symbol-level equalization has proven to be problematic due to long spreading sequences employed in downlink. To circumvent the problem, receivers based on channel equalization at chip level have been proposed to ensure adequate performance even with a high number of active users. In this paper, a symbol-level equalizer is introduced. The equalizer provides significant complexity reduction over the chip-level equalizer without compromising the performance. The numerical results show significant performance improvement over the conventional Rake receiver with a high number of active users in a Rayleigh fading multipath channel.