Randall W. Rich - Lake Villa IL Richard J. Vilmur - Palatine IL
Assignee:
Motorola, Inc. - Schaumburg IL
International Classification:
H04B 106 H04B 700
US Classification:
4552341
Abstract:
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).
Dual Mode Radio Subscriber Unit Having A Diversity Receiver Apparatus And Method Therefor
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).
Power Control Circuit For A Radio Frequency Transmitter
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).