The impacts of SDMA on PCS system design

The goal of a personal communications service (PCS) system is to provide ubiquitous coverage for a wide variety of wireless services: voice, data, facsimile, and electronic mail to name but a few. The current design trend for these systems is to deploy a large number of small cells, each served by a base station incorporating a conventional antenna system. Although this approach addresses the coverage problem, it has a number of significant drawbacks. Large numbers of small cells result in reduced trunking efficiency, increased system complexity, increased system costs and increased deployment times. If antenna arrays coupled with adaptive signal processing techniques are employed at the base station, however, improved coverage, capacity and trunking efficiency can be obtained with cells of moderate to large size. Spatial division multiple access (SDMA) is a particular approach to the use of base station antenna arrays in PCS systems. The authors describe the fundamentals of the SDMA approach and its key impacts on the design of PCS systems