A TDMA indoor radio communications system using cyclical slow frequency hopping and coding-experimental results and implementation issues

The authors describe the principle, implementation, and performance of an experimental 1.5-GHz radio communications system within a medium-size office building. The system features 1-Mb/s TDMA (time division multiple access) for service flexibility and slow frequency hopping and coding for immunity against multipath fading and interference. Measurements show that with a hallway-mounted distributed antenna system and with the mobile unit transmitting only 1 mW of peak RF power, only a single 384-bit frame out of a total of about 200,000 transmitted frames suffered an unrecoverable error. The same excellent performance was obtained from a central antenna, but only with the transmitted power increased to 100 mW