Abstract: An image reject mixer for a low power battery operated radio telephone application. First and second doubly balance mixer circuits are connected to receive a differential radio frequency signal. Each of the doubly balance mixer circuits receives a local oscillator signal and a complimentary quadrature local oscillator signal. A first and second differential current produced by the first and second doubly balance mixture are combined in a quadrature combining circuit. The quadrature combining circuit adds an additional 90° of phase shift between the pairs of signals produced by each doubly balance mixture, so that the mixture output signals are added in a phase quadrature relationship thereby canceling unwanted spur and image components contained in the respective mixer output circuits.

Abstract: In the conventional diversity reception, information included in each non-selected signal does not contribute to an improvement in the reliability of communications, and transmitting power has been dissipated to satisfy required communication quality. Owing to the setting of encoding in respective base stations to injection, signals each including the same contents, which are received by a mobile station, are used for increasing the reliability of communications without depending on the number of the signals which were capable of being received by the mobile station, to thereby reduce transmitting power for satisfying required communication quality.

Abstract: A method and system are disclosed for automatically disabling termination restrictions of a mobile subscriber unit in response to a disconnection of an emergency call originated by said mobile subscriber unit. According to the present invention, a determination is first made that an emergency call has been originated from a mobile subscriber unit to a public safety answering point. Next, in response to a disconnection of the emergency call, a subscriber database that contains the termination restriction is automatically notified that the emergency call has been disconnected. Finally, in response to automatically notifying the subscriber database that the emergency call has been disconnected, the termination restriction is automatically disabled for a limited period of time, such that the public safety answering point may call the mobile subscriber unit back.