Field Trial Results of 4-Way Receive Diversity in a Live GSM Network

Receive diversity is an efficient means to improve base station receiver sensitivity and thereby coverage of wireless communication systems. While 2-way receive diversity (2WRD) has been commercially available for different standards for a long time, this paper reports the improvements seen in a field trial of 4-way receive diversity (4WRD) conducted in a live GSM network. The results are also compared to what can be expected theoretically and shown by computer simulations. Depending on the conditions for the trial (e.g. set-up and propagation environment), theory and computer simulations suggest that the expected gain of 4WRD over 2WRD should be in the order of 3-5 dB. The performance measurements carried out during the trial verifies this expected gain. For example, when all traffic in the cell is used as basis for the measured statistics, the cell averaged 4WRD gain over 2WRD is in the order of 3.5-4 dB