Radio communication device and method capable of reducing power consumption by controlling an A/D converter
First Claim
1. A method of controlling electric power in a radio communication device which has an analog-to-digital (A/D) converter and which is used in a code division multiple access (CDMA) system, the radio communication device being operable in a selected one of a high power mode and a low power mode, the method comprising the steps of:
- detecting each of the high and low power modes by monitoring the perching channel to determine if the receiver is in standby mode to produce a detection signal representative of either one of the high and the low power modes; and
operating the A/D converter in the low power mode in response to the detection signal, as compared with the high power mode;
wherein the A/D converter is operated in lower power mode when the receiver is in standby mode.
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Accused Products
Abstract
In a radio communication device of a CDMA system selectively operable in high and low power modes to receive a reception analog signal and to produce a demodulated signal, an A/D converter is controlled to reduce power consumption in the low power mode in comparison with the high power mode. The reduction of power consumption can be established by partially operating the A/D converter or by lowering a sample rate in the low power mode. A despreading portion connected to the A/D converter is also controlled in a manner similar to the A/D converter. Each of the high and the low power modes is indicated by a mode control signal produced by a CPU controller.
38 Citations
25 Claims
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1. A method of controlling electric power in a radio communication device which has an analog-to-digital (A/D) converter and which is used in a code division multiple access (CDMA) system, the radio communication device being operable in a selected one of a high power mode and a low power mode, the method comprising the steps of:
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detecting each of the high and low power modes by monitoring the perching channel to determine if the receiver is in standby mode to produce a detection signal representative of either one of the high and the low power modes; and
operating the A/D converter in the low power mode in response to the detection signal, as compared with the high power mode;
wherein the A/D converter is operated in lower power mode when the receiver is in standby mode. - View Dependent Claims (2, 3)
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4. A radio communication device responsive to a reception analog signal and operable in a selected one of high and low power modes to demodulate the reception analog signal into a demodulated signal, the device comprising:
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an analog-to-digital (A/D) converter for converting the reception analog signal into a digital signal;
means for processing the digital signal into the demodulated signal; and
a control circuit for controlling the A/D converter so that electric power consumption of the A/D converter is reduced in the lower power mode as compared with the high power mode when a receiver is determined to be in standby mode by monitoring a perching and a paging channel for control signals. - View Dependent Claims (5, 6, 7)
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8. A radio communication device for demodulating a reception analog signal into a demodulate signal, comprising:
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an analog-to-digital (A/D) converter for converting the reception analog signal into a digital signal so that a bit number of the digital signal is variable;
wherein the A/D converter has low and high significant bit parts both of which are operable to produce a first part and a second part of the digital signal, respectively;
the A/D converter selectively producing a selected one of the first and the second parts and a combination of the first and the second parts so as to vary the bit number of the digital signal. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A radio communication device operable in response to a reception analog signal to produce a demodulated signal, comprising:
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an A/D converter for converting the reception analog signal into a digital signal; and
a controllable sampling signal generator for selectively supplying the A/D converter with a first sampling signal of a first sample rate and a second sampling signal of a second sample rate different from the first sample frequency;
the A/D converter being operable in response to either one of the first and the second sampling signals and the reception analog signal to produce the digital signal which has the bit number determined by either one of the first and the second samples rates, wherein the first rate is used when operating in transmission/reception mode and the second sample ratio is used in standby mode and where the standby mode is determined by monitoring the perching and paging channels for control signals instead of speech signals. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25)
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Specification