Power Control at the Combiner Output to Maximize the Uplink Capacity on a Cellular Spread Spectrum System

The benefits of applying maximal ratio combining instead of selection combining when using macrodiversity in a cellular code-division multiple access (CDMA) system were studied. In particular, using maximal ratio combining with power control made at the combiner output, and assuming equal interference at every base station, we provide a simple proof to show that we can achieve on the uplink the same capacity per cell as with an isolated cell. On extending the study to a practical case with a limited number of cells in macrodiversity in comparison with the unrestricted theoretical case, we found that the results on cell capacity with maximal ratio combining were quite close to the results with an isolated cell.