Abstract: A method is provided for operating a two-way communications service station having a maximum transmitter power adapted to avoid interference to broadcast station receivers. The communications service station shares a frequency band with the broadcast service station transmitter. The method includes periodically tuning the communications service station to the frequency band being used by the broadcast service station and detecting the presence of signals above a predetermined power level on frequencies known to be used by the broadcast station. The method further includes raising the maximum transmitter power limit for the two-way communications service station to a higher power level if the power level of the detected signal is above the predetermined power level.

Abstract: A wireless communications system is provided with reduced sideband noise and carrier leakage. In the system, at least one transmitter modulates at least one input signal with a first carrier to generate a modulated output signal, and at least one receiver receives the modulated output signal and demodulates the same with a second carrier to generate at least one demodulated output signal. The first and second carriers are at different frequencies, such that the sideband noise and carrier leakage generated by different sources can be distinguished.

Abstract: A method and system is disclosed for passing a transmit/receive control signal and a power signal through a coax cable from a base transceiver station to a tower top device in a time division duplex communication system. After generating the transmit/receive control signal and a radio frequency signal for communications, the transmit/receive control signal modulates a separate timing control operating on a separate control frequency. It is then multiplexed on at least one coax cable along with the radio frequency signal and DC power. At the tower top device, the modulated transmit/receive control signal is converted back to a DC level for providing a time division duplex control reference.

Abstract: A radio frequency (RF) power combiner for connecting multiple base transceiver stations with one antenna assembly includes at least one combining device coupled to at least two base transceiver stations for combining signals generated thereby into a combined signal for being transmitted by the antenna assembly. At least one frequency selective RF power detector is coupled to one of the signals generated from one of the base transceiver stations for generating an output indicating whether the signal at a predetermined frequency is present. A logic control module is coupled to the frequency selective RF power detector for generating a control signal in response to the output of the detector. An oscillator is coupled to the logic control module for generating a carrier signal at the predetermined frequency for the combined signal in response to the control signal.

Abstract: The method for operating a two-way communications service station having a maximum transmitter power adapted to avoid interference to broadcast station receivers is disclosed. The communications service station shares a frequency band with the broadcast service station transmitter. The method includes periodically tuning the communications service station to the frequency band being used by the broadcast service station and detecting the presence of signals above a predetermined power level on frequencies known to be used by the broadcast station. The method further includes raising the maximum transmitter power limit for the two-way communications service station to a higher power level if the power level of the detected signal is above the predetermined power level.

Abstract: The present invention discloses a wireless communications system with reduced sideband noise and carrier leakage. In the system, at least one transmitter modulates at least one input signal with a first carrier to generate a modulated output signal, and at least one receiver receives the modulated output signal and demodulates the same with a second carrier to generate at least one demodulated output signal. The first and second carriers are at different frequencies, such that the sideband noise and carrier leakage generated by different sources can be distinguished.

Abstract: A method and system is disclosed for passing a transmit/receive control signal and a power signal through a coax cable from a base transceiver station to a tower top device in a time division duplex communication system. After generating the transmit/receive control signal and a radio frequency signal for communications, the transmit/receive control signal modulates a separate timing control operating on a separate control frequency. It is then multiplexed on at least one coax cable along with the radio frequency signal and DC power. At the tower top device, the modulated transmit/receive control signal is converted back to a DC level for providing a time division duplex control reference.

Abstract: A radio frequency (RF) power combiner for connecting multiple base transceiver stations with one antenna assembly includes at least one combinational logic device coupled to at least two base transceiver stations for combining signals generated thereby into a combined signal for being transmitted by the antenna assembly. At least one frequency selective RF power detector is coupled to one of the signals generated from one of the base transceiver stations for generating an output indicating whether the signal at a predetermined frequency is present. A logic control module is coupled to the frequency selective RF power detector for generating a control signal in response to the output of the detector. An oscillator is coupled to the logic control module for generating a carrier signal at the predetermined frequency for the combined signal in response to the control signal.

Abstract: There is disclosed an ACP monitoring circuit for use in a wireless network comprising a plurality of base stations for communicating with a plurality of mobile devices. Each of the plurality of base stations comprises an RF transmitter that receives an input baseband signal and an RF carrier signal and produces a modulated RF output signal that is then amplified. The ACP monitoring circuit monitors adjacent channel power (ACP) noise in the RF output signal. The ACP monitoring circuit comprises: 1) an RF mixer having a first input receiving the RF output signal and a second input receiving the RF carrier signal and produces a scaled output signal on an output of the RF mixer; and 2) a first power detection circuit coupled to the RF mixer output that determines a power level of the ACP noise outside an allocated channel bandwidth of the RF transmitter.

Abstract: A measurement and calibration circuit is disclosed for use in a RF transceiver comprising an antenna and a RF receiver, having a receive path, coupled to the antenna. The measurement and calibration circuit comprises: a test signal generator for generating a known amplitude and frequency test signal; a switch having an input coupled to the test signal generator, a first output coupled to an input of the receive path, and a second output coupled to the antenna; a test controller for causing the switch to directly inject the test signal into the input of the receive path and causing the switch to inject the test signal into the antenna, wherein the antenna at least partially reflects the test signal into the receive path; and a signal monitor coupled to an output of the receive path for measuring the direct injected test signal and the reflected test signal.

Abstract: There is disclosed, for use in an RF amplifier, a biasing circuit for maintaining the quiescent current of an output power transistor at a selected bias level. The biasing circuit comprises a temperature sensor circuit for generating a temperature-sensitive control voltage that varies according to changes in temperature of the output power transistor and a bias voltage generating circuit capable of detecting a variation in the temperature-sensitive control voltage. In response to a detected change in the temperature-sensitive control voltage, the bias circuit adjusts a bias voltage applied to the output power transistor by an amount suitable to offset a change in the selected bias current level caused by a temperature change related to the variation in the temperature-sensitive voltage.