Capacity enhancement of narrowband CDMA by intelligent antennas

Abstract

A standard-compatible upgrade of IS95-CDMA base station (BS) transceivers by smart antennas can at least double the cellular radio capacity at the cost of a moderately increased transceiver complexity. This is demonstrated for the adoption of a beam diversity concept. At the sectorized BS, uniform linear antenna arrays are employed. An intelligent adaptive receiver antenna is implemented based on the DFT beamspace transform and angular-temporal RAKE combining. Downlink transmission utilizes beam selection. In Monte-Carlo-based performance assessments a special point of emphasis is put on the real-world-like modeling of the directional radio propagation phenomena. Small and large area channel models for densely built-up urban macro-cells are used which were determined from the results of a spatio-temporally sensitive sounding campaign at 1.9 GHz. Thus, the analysis results are valid for the important application case of larger urban cells operated in the PCS and IMT-2000 bands.