Abstract: There is described a circuit for transmitting a transmit signal at a transmit frequency and receiving a receive signal at a receiver frequency, for use with a common antenna, comprising: a first signal junction having a transmit port for receiving the transmit signal, a receive port for outputting the receive signal, a third port and a fourth port, wherein the third and fourth port are for outputting a pair of common mode or differential mode transmit signals which are split from the transmit signal at the transmit port, and for receiving a pair of common mode or differential mode receive signals which are combined and provided to the receive port; a second signal junction having an antenna port for connection to an antenna, a second port and a third port, wherein the second and third port are for outputting the pair of common mode or differential mode receive signals which are split from the signal received at the antenna port, and for receiving the pair of common mode or differential mode transmit signals w

Abstract: A signal isolation control apparatus for controlling duplexing of signals to be transmitted through and received from an antenna. The apparatus includes a transmitter chain tap input for coupling to a transmitter chain. An auxiliary transmitter chain is operably coupled to the transmitter chain tap input for processing a transitory signal tapped from the transmitter chain, the auxiliary transmitter chain including an adaptive filter unit and a balance node output for operably coupling to a balance node of a hybrid junction. The adaptive filter unit has a signal leakage monitoring input for operably coupling to an output node of the hybrid junction. The auxiliary transmitter chain is arranged to process the tapped transitory signal in order to generate and apply an isolation signal at the balance node output for maximizing isolation of an output node of the hybrid junction from an input node of the hybrid junction.

Abstract: A signal isolation control apparatus for controlling duplexing of signals to be transmitted through and received from an antenna. The apparatus includes a transmitter chain tap input for coupling to a transmitter chain. An auxiliary transmitter chain is operably coupled to the transmitter chain tap input for processing a transitory signal tapped from the transmitter chain, the auxiliary transmitter chain including an adaptive filter unit and a balance node output for operably coupling to a balance node of a hybrid junction. The adaptive filter unit has a signal leakage monitoring input for operably coupling to an output node of the hybrid junction. The auxiliary transmitter chain is arranged to process the tapped transitory signal in order to generate and apply an isolation signal at the balance node output for maximising isolation of an output node of the hybrid junction from an input node of the hybrid junction.

Abstract: A cellular radio telecommunication system is described that allows the beacon frequencies in the system that distributes the common control channel to carry more traffic channels than the number of remaining TDM slots, by reusing the same slot in different parts of the network to carry different traffic to different mobiles. This is achieved by monitoring the location in the network of each mobile which is assigned to a traffic channel on the beacon frequency, using a controlling agent, and ensuring that any basestation assigned to the beacon frequency which is sufficiently close to this mobile transmits exactly the same data in the slot carrying this traffic channel, but otherwise allows the slot to be reallocated.