Cellular radio telephone enhancement circuit

Abstract

For use in a cellular radio-telephone system to enhance a signal from a cell site in an area shadowed by an obstruction such as a building or a mountain or the like, and to receive signals from subscribers in such areas, a cell enhancer includes bidirectional receivers, transmitters and amplifiers, the receivers and transmitters both including duplexer circuits for coupling signals in the proper up-link and down-link bands to the proper up-link and down-link antennas for transmission. Two embodiments of amplifiers are disclosed. A wideband amplifier network includes an input duplexer, a wideband amplifier with an attenuator, and an output duplexer, the duplexers coupling signals from both the up-link and down-link duplexer circuits to the amplifier for amplification. A narrow band network includes a plurality of amplifier modules each of which amplify only on one up-link and down-link channel assigned to the cell. A signal divider couples signals in the appropriate channels to the inputs of the corresponding modules, and a signal combining circuit receives signals from the modules to generate a composite signal for transmission by the up-link and down-link antennas. The enhancer further includes a control circuit responsive to signals from the cell site received through the amplifier for controlling the operations of the enhancer and for reporting to the cell site the status of the enhancer by transmitting signals through the enhancer.