IMPROVEMENTS IN OR RELATING TO A METHOD AND APPARATUS FOR DETERMINING SYMBOL TIMING IN A WIRELESS COMMUNICATIONS SYSTEM, ALSO USING A REUSABLE CONTROL CHANNEL, AND REDUCING POWER

摘要

A wireless communication system in which a base station communicates with plural mobile stations using a control channel and plural voice (or data) channels, and uses the control channel as a voice channel whenever the other voice channels are in use and a request is received from a mobile station for another voice channel. Also a method and apparatus for reducing power consumed by mobile, wireless units, such as personal communications systems or wireless PBX telephones, by reducing the frequency with which various circuits within the units are fully energized. During on-going voice communications between a base station and a wireless unit, the wireless unit reduces the frequency of its references to a control channel and may eliminate such references altogether. Moreover a method and apparatus for determining the timing of symbols within a multiple symbol telecommunicated message by evaluating signal characteristics in both the preamble and data portions of a message. Samples of a received signal are taken at a periodic basis and a predetermined characteristic of the signal is evaluated for each sample.