Random access control channel gain control and time slot recovery for remote in-band translator in time division multiple access wireless system

摘要

In a conventional Time Division Multiple Access (TDMA) wireless system, the specified distance between a mobile unit and the base transceiver system (BTS) cannot exceed predetermined distances because of time slot synchronization constraints. Furthermore, the varying distances between mobile units and the BTS create timing differences in the random access control channel (RACCH) bursts in the initial uplink signal from the mobile stations. In this approach to extending TDMA system coverage, in-band translator components are located in the center of remote cells which would normally contain a base transceiver system. The in-band translators include a loop back circuit that permits a host BTS to measure the backhaul propagation time delay by sending test access signals between the host BTS and the distant in-band translators.After backhaul timing delay is compensated in the BTS, then the in-band translator uses downlink time slot recovery to synchronize slot-by-slot uplink diversity selection and automatic level control.Recovery of timing bursts on downlink from the BTS allows for determination of burst, frame, and multiframe timing for downlink and uplink in the in-band translator. Processing allows for pre-determination of which uplink time slots that the RAACH signal can appear from the mobile unit. This method allows for automatic level control during RAACH bursts in addition to normal uplink bursts.