Properties of a TDMA pico cellular office communication system

Properties of a TDMA/TDD (time-division multiple access/time-division duplex) micro or rather pico cellular cordless telephone system using decentralized dynamic channel allocation and handover are presented. The system has 16 or 8 time-division time-duplex channels (slots) per carrier, each occupying 2 MHz or 1MHz. The TDMA frame is 16 ms long and each slot has bits for synchronization, signalling, and data. The data speed is suited for 32 kb/s speech codecs. Procedures have been developed for efficient and quick dynamic channel allocation and handover, using the fact that a single radio can simultaneously monitor or communicate on all 16 or 8 time-slot channels. Simulations for a specific six storey building indicate that 16 channels can provide wireless communications for up to 30% of the telephones, and 32 channels for up to 100% of the telephones. Slot synchronization between adjacent systems is desirable, but not necessary. Tests show that no time dispersion equalizers are needed, and that antenna diversity is effective against fading dips and time dispersion. This system concept has been proposed to CEPT as a base for European Digital Cordless Telecommunications