Motorola Corporation

Other

Randall Wayne Rich

Thomas J Walczak

Richard J Vilmur

Stephen V Cahill

Rashid M Osmani

Dale Gerard Schwent

Eugene J Bruckert

Rashid M Osman

Richard Joseph Vilmur

A radio subscriber unit (102) comprises a controller (108) and a switched antenna diversity receiver apparatus (106) including a first antenna (114), a second antenna (116) and a receiver (126). The first antenna (114) is adapted to receive a first representation (158) of a radio frequency (RF) signal (156). The second antenna (116) is adapted to receive a second representation (160) of the RF signal (156). The receiver (126), selectively coupled to the first antenna (114) and the second antenna (116), generates a received signal (153) responsive to receiving at least one of the first representation (158) of the RF signal (156) from the first antenna (114) and the second representation (160) of the RF signal (156) from the second antenna (116). The controller (108), coupled to the receiver (126), selectively couples to the receiver (126), responsive to the received signal (153), one of: only the first antenna (114), only the second antenna (116) and both the first antenna (114) and the second antenna (116).

Radio subscriber unit having a switched antenna diversity apparatus and

A dual mode cellular radiotelephone subscriber unit (802) comprises a diversity receiver (812) and a controller (814). The diversity receiver (812) receives either a first radio frequency (RF) signal (808) modulated by a digital modulation method (805) or a second RF signal (810) modulated by an analog modulation method (807). In one embodiment, the controller (814) controls the diversity receiver (812) responsive to a first diversity algorithm (834) when the diversity receiver (812) receives the first RF signal (808) modulated by the digital modulation method (805), and responsive to a second diversity algorithm (836) when the diversity receiver (812) receives the second RF signal (810) modulated by the analog modulation method (836). In another embodiment, the controller (814) controls the diversity receiver (812) responsive to a first received information set (835) when the diversity receiver (812) receives the first RF signal (808) modulated by the digital modulation method (805), and responsive to a second received information set (837) when the diversity receiver (812) receives the second RF signal (810) modulated by the analog modulation method (807).

Dual mode radio subscriber unit having a diversity receiver apparatus

A gain controller (130) for a radio frequency (RF) transmitter (102) controls a power level of a signal (123) transmitted within a predetermined range of output power levels. The gain controller (130) provides the first gain control signal (131) and the second gain control signal (133) responsive to an output power level control signal (150). The first gain control signal (131) controls a gain of a first variable gain stage (144) to vary the power level of the transmit signal (115) at an intermediate frequency causing the output power level of the transmit signal (123) to vary over a lower range of the predetermined range of output power levels. The second gain control signal (133) controls a gain of the second variable gain stage (120) to vary the power level of the transmit signal (121) at a radio frequency causing the output power level of the transmit signal (123) to vary over an upper range of the predetermined range of output power levels. The power control circuit (130) is advantageously utilized in a code division multiple access (CDMA) radiotelephone (100) to provide power control over an 85 dB range of power levels while minimizing sideband noise emissions, current drain, and complexity of the RF transmitter (102).

Power control circuit for a radio frequency transmitter

A code division multiple access (CDMA) radio receiver (104) having gain receives a radio frequency (RF) signal (122) to produce a received signal (124). The quality (130) of the received signal (124) is determined (111). The quality (130) is preferably a ratio of an energy per chip of a desired signal (Ec) to a total power spectral density of the received signal (Io) (124). For alternative radio receivers (104) the quality (130) may be an error rate estimate of a demodulated signal (126). The gain of the radio receiver (104) is adjusted responsive to the quality (130) of the received signal (124) to optimize the quality (130) of the received signal (124). Further, since the adjusted gain also changes a received signal strength indication (RSSI) (242) of the received signal (124), the RSSI (242) of the received signal (124) is estimated (217) and compensated (218) responsive to the gain of the radio receiver (104) to produce a compensated RSSI (134) of the received signal (124) indicative of the RSSI of a desired RF signal (122).

Apparatus and method for optimizing the quality of a received signal in

A cellular telephone transmitter (100) includes a variable-gain power amplifier (102), the output of which is filtered and sampled by a filter (104) with an integral directional coupler. Filter (104) includes both a transmitter signal filter and a directional coupler on a ceramic block of one or more pieces. The directional coupler has been realized by two coupled transmission lines provided by the two holes (206 and 207) on the left side of the ceramic block, and the transmitter filter has been realized by five short-circuited coupled transmission lines provided by the five holes (201-205) on the right side of the ceramic block.

Transmitter filter with integral directional coupler for cellular

A gain control system for controlling signal levels of the signal received by a receiver. The gain control system is operable to control the signal levels of the signal when the signal is comprised of either a conventional, constant envelope signal, such as an FM signal, or a non-constant envelope signal, such as a TDMA composite modulated signal. The gain control system may be advantageously embodied in a dual-mode radiotelephone operable to receive both conventional, FM signals and TDMA, composite modulated signals.

Dual mode automatic gain control

A frequency control system for a dual-mode radiotelephone (152-238; 252-320) operative to receive either an FM signal or a DQPSK signal. In a first embodiment, when operative to receive the FM signal, the frequency of the reference oscillator (192) of the radiotelephone (152-222) is maintained in a fixed relation with the frequency of the FM signal. When operative to receive the DQPSK signal, the reference oscillator (192) is maintained in a fixed relation with the frequency of the DQPSK signal as determined by a digital signal processor (212). In a second embodiment, when operative to receive the FM signal, the frequency of an offset control oscillator (320) is maintained in a fixed relation with the frequency of the FM signal. When operative to receive the DQPSK signal, the reference oscillator (292) is maintained in a fixed relation with the frequency of the DQPSK signal as determined by a digital signal processor (312).

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Lake Villa, IL, United States of America

Randall Wayne Rich