Current reduction by receiver linearity adjustment in a communication device
First Claim
1. A method for reducing current drain in a communication device operating on a traffic channel in a code division multiple access (CDMA) system, the method comprising the steps of:
- enabling the receiver;
determining when the communication device is transmitting;
measuring a received signal strength and measuring a level of the transmitter power if the transmitter is gated on;
lowering a bias current level to a preset level to operate the receiver in a non-linear mode and adjusting a receiver power amplifier gain level only dependent upon the received signal strength when the communication device is not transmitting; and
raising the bias current level to the receiver to operate the receiver in a linear mode with the current level dynamically dependent upon the transmitter power and adjusting a receiver power amplifier gain level dependent upon the received signal strength when the communication device is transmitting and keeping the bias current low if the gain level is at a nominal or lower state dependent upon the received signal strength.
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Accused Products
Abstract
A method for reducing current drain in a communication device includes a step of determining when the communication device is transmitting. A next step includes lowering the current level to the receiver when communication device is not transmitting. A next step includes raising the current level to the receiver when communication device is transmitting. Changing the current level alters the linearity of the receiver. As a result, the communication device reduces power consumption while operating in a traffic channel. The system is applicable to full duplex systems such as code division multiple access (CDMA) systems.
20 Citations
11 Claims
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1. A method for reducing current drain in a communication device operating on a traffic channel in a code division multiple access (CDMA) system, the method comprising the steps of:
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enabling the receiver;
determining when the communication device is transmitting;
measuring a received signal strength and measuring a level of the transmitter power if the transmitter is gated on;
lowering a bias current level to a preset level to operate the receiver in a non-linear mode and adjusting a receiver power amplifier gain level only dependent upon the received signal strength when the communication device is not transmitting; and
raising the bias current level to the receiver to operate the receiver in a linear mode with the current level dynamically dependent upon the transmitter power and adjusting a receiver power amplifier gain level dependent upon the received signal strength when the communication device is transmitting and keeping the bias current low if the gain level is at a nominal or lower state dependent upon the received signal strength. - View Dependent Claims (2, 3, 4)
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5. A method for reducing current drain in a communication device operating on a traffic channel in a code division multiple access (CDMA) system, the method comprising the steps of:
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enabling the receiver;
determining when the communication device is transmitting;
measuring a received signal strength and measuring a level of the transmitter power if the transmitter is gated on;
lowering a bias current level to a preset level to operate the receiver in a non-linear mode and adjusting a receiver power amplifier gain level only dependent upon the received signal strength when die communication device is not transmitting such that the communication device meets intermodulation requirements; and
raising the bias current level to the receiver to operate the receiver in a linear mode with the current level dynamically dependent upon the transmitter power and if a received signal strength is within a predetermined range from the transmitted power, adjusting a receiver power amplifier gain level dependent upon the received signal strength when the communication device is transmitting and keeping the bias current low if the gain level is at a nominal or lower state dependent upon the received signal strength such that the communication device meets intermodulation and crossmodulation requirements. - View Dependent Claims (6, 7)
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8. A communication device with reduced current drain on a CDMA traffic channel, the communication device comprising:
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a transmitter operable to be gated off and to be gated on while incorporating a variable transmit power level;
a receiver operable at a variable receive bias current and voltage gain levels, the receiver is always on during communication; and
a control circuit coupled to the transmitter and receiver, the control circuit operable to measure a received signal strength and to control the receiver linearity, wherein when the transmitter is operating the control circuit directs the receiver to operate in a linear mode with the current level dynamically dependent upon transmitter power and at a receiver power amplifier gain level only dependent upon the received signal strength and keeps the bias current low if the gain level is at a nominal or lower state dependent upon the received signal strength, and when the transmitter is not operating the control circuit directs the receiver to operate at a preset current level in a non-linear mode and at a receiver power amplifier gain level dependent upon the received signal strength. - View Dependent Claims (9, 10, 11)
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Specification