EFFICIENT FREQUENCY UTILIZATION TECHNIQUES FOR HIGH-CAPACITY LAND MOBILE COMMUNICATION SYSTEM.

This paper discusses techniques for frequency utilization factor improvement in the High-Capacity Land Mobile Communication System under development at NTT. It is shown that a channel separation of 12. 5 kHz miximizes the frequency utilization factor in terms of both of available channel number and geographical reuse. Improvement in both tolerance against interference and geographical reuse factor is quantitatively discussed for diversity reception. It is also shown that an interference reduction of about 3db can be achieved via detection of increased interference and changing of radio channels to lower the interference.