Time-division duplex CDMA communications

The authors examine the time-division duplex (TDD) mode of code-division multiple access (CDMA) communications. The differences from frequency-division duplex (FDD) are shown, and the advantages of using a TDD system are discussed. The TDD mode facilitates the implementation of several functions in the areas of power control, RAKE combining, and selection diversity combining, which can reduce the complexity of mobile units and improve system capacity.