Low-cost direct conversion receiver structures for TDMA mobile communications

Future public land mobile telecommunication systems (FPLMTS) with robust digital transmission will require cheap, small, and low-power mobile terminals. This goal can be reached by a receiver architecture which lends itself to VLSI and which does not require any adjustments during the production process. The authors have studied a number of direct-conversion receiver structures. A receiver based on the incoherent direct conversion principle with differential data detection was investigated candidate system for TDMA mobile communications. A typical application would be the proposed Digital European Cordless Telecommunication (DECT) system where a data rate of more than 1 Mbit/s is envisaged. The author describes the architecture of the receiver and key components, e.g. the synchronization unit and the algorithm of the fast gain control unit. Both are needed for operation in a TDMA system. Solutions to overcome the blocking problems of a direct conversion architecture are presented. The receiver performance is characterized by error rates in the presence of noise, of adjacent-channel signal and of co-channel signals