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4965809 Uplink cross-polarization interference canceller using correlation calculator and stepwise tracking controller
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New Patents
4965607
ference between the previous and recent values is substantially reduced to a minimum.
ANTENNA COUPLER Mark L Wilkins, Alvin Wong assigned to BR Communications lnc An automatic antenna coupler is disclosed. The antenna coupler automatically matches the output impedance of a 50-ohm transmitter to the input impedance of a non-broad-band antenna, such as a whip, dipole or long wire. The resulting increase in transmit coupling el~.ciency provides greater radiative power than that available from an unmatched antenna.
4965809 UPLINK CROSS-POLARIZATION INTERFERENCE CANCELLER USING CORRELATION CALCULATOR AND STEPWISE TRACKING CONTROLLER Kazuhit Endo, Tokyo, Japan assigned to NEC Corporation In a satellite communications system, a rotatable 90 degrees phase shifter and a rotatable 180 degrees phase shifter introduce variable phase shifts to a single pilot signal, which is transmitted to the satellite. Downlink crosspolarization interference cancelling- control signals are derived from a beacon signal received from the satellite. A pulse sequence is generated to modulate the amplitude of a carrier to produce an ASK signal as the pilot signal. A correlation calculator provides coarse mode interference cancellation by estimating uplink cross-polarization interference components from the downlink cross-polarization cancelling control signals and adjusting the angle settings of the 90 degrees and 180 degrees phase shifters with the estimated components..The pilot signal is transmitted back to the earth and synchronously detected with the pulse sequence to derive a DC signal which represents an uplink cross-polarization interference. A stepwise tracking controller provides fine mode interference cancellation by stepwisely varying the 90 degrees and 180 degrees phase shifters by predetermined amounts an detecting previous and recent values of the synchronously detected DC signal resulting from the stepwise variations, and repeating the stepwise variations until a dif-
4965849 CORDLESS TELEPHONE Takushi Kunihiro, Kanagawa, Japan assigned to Sony Corporation A cordless telephone of multi-channel access (MCA) type has a master station which includes a plurality of sets of transmitting and receiving circuits and communication channels are simultaneously opened between the master station and a plurality of remote stations or handset units. The master station is controlled, as by a microcomputer, so that a receiving circuit in the master station sequentially scans communication channels to produce data indicating a vacant channel and which is to be stored in a memory as vacant channel information~ a communication channel indicated to be a vacant channel by the stored information is employed when a communication channel is opened between the master station and the remote stations, when data indicating a vacant communication channel is to be stored in the memory as vacant channel information, it is determined whether or not such vacant communication channel disturbs a control channel or other communication channels by cross modulation, and, when the vacant communication channel is determined to be a channel which causes a cross modulation disturbance, the data indicating such communication channel is inhibited from being stored in the memory.
4965850 SYSTEM FOR AND M'ETHOD OF A S S I G N I N G F R E Q U E N C I E S IN A COMMUNICATIONS SYSTEM WITH NO CENTRAL CONTROL OF FREQUENCY ALLOCATION Jerry Schloemer A system for and method of assigning frequencies in a mobile telephone communication system wherein there is no central control of frequency channel allocations and wherein such assignment is made by real time signal comparisons without reference to geographical patterns.
New Patents
4965607
ference between the previous and recent values is substantially reduced to a minimum.
ANTENNA COUPLER Mark L Wilkins, Alvin Wong assigned to BR Communications lnc An automatic antenna coupler is disclosed. The antenna coupler automatically matches the output impedance of a 50-ohm transmitter to the input impedance of a non-broad-band antenna, such as a whip, dipole or long wire. The resulting increase in transmit coupling el~.ciency provides greater radiative power than that available from an unmatched antenna.
4965809 UPLINK CROSS-POLARIZATION INTERFERENCE CANCELLER USING CORRELATION CALCULATOR AND STEPWISE TRACKING CONTROLLER Kazuhit Endo, Tokyo, Japan assigned to NEC Corporation In a satellite communications system, a rotatable 90 degrees phase shifter and a rotatable 180 degrees phase shifter introduce variable phase shifts to a single pilot signal, which is transmitted to the satellite. Downlink crosspolarization interference cancelling- control signals are derived from a beacon signal received from the satellite. A pulse sequence is generated to modulate the amplitude of a carrier to produce an ASK signal as the pilot signal. A correlation calculator provides coarse mode interference cancellation by estimating uplink cross-polarization interference components from the downlink cross-polarization cancelling control signals and adjusting the angle settings of the 90 degrees and 180 degrees phase shifters with the estimated components..The pilot signal is transmitted back to the earth and synchronously detected with the pulse sequence to derive a DC signal which represents an uplink cross-polarization interference. A stepwise tracking controller provides fine mode interference cancellation by stepwisely varying the 90 degrees and 180 degrees phase shifters by predetermined amounts an detecting previous and recent values of the synchronously detected DC signal resulting from the stepwise variations, and repeating the stepwise variations until a dif-
4965849 CORDLESS TELEPHONE Takushi Kunihiro, Kanagawa, Japan assigned to Sony Corporation A cordless telephone of multi-channel access (MCA) type has a master station which includes a plurality of sets of transmitting and receiving circuits and communication channels are simultaneously opened between the master station and a plurality of remote stations or handset units. The master station is controlled, as by a microcomputer, so that a receiving circuit in the master station sequentially scans communication channels to produce data indicating a vacant channel and which is to be stored in a memory as vacant channel information~ a communication channel indicated to be a vacant channel by the stored information is employed when a communication channel is opened between the master station and the remote stations, when data indicating a vacant communication channel is to be stored in the memory as vacant channel information, it is determined whether or not such vacant communication channel disturbs a control channel or other communication channels by cross modulation, and, when the vacant communication channel is determined to be a channel which causes a cross modulation disturbance, the data indicating such communication channel is inhibited from being stored in the memory.
4965850 SYSTEM FOR AND M'ETHOD OF A S S I G N I N G F R E Q U E N C I E S IN A COMMUNICATIONS SYSTEM WITH NO CENTRAL CONTROL OF FREQUENCY ALLOCATION Jerry Schloemer A system for and method of assigning frequencies in a mobile telephone communication system wherein there is no central control of frequency channel allocations and wherein such assignment is made by real time signal comparisons without reference to geographical patterns.