Method and apparatus for transmitting and receiving signals
First Claim
1. A dual-mode receiver operable to receive signals in a first mode having an associated first channel spacing, and to receive signals in a second mode having an associated second channel spacing smaller than the first channel spacing, comprising:
- first and second front-end RF stages for receiving a signal transmitted in the first mode at a first carrier frequency and the second mode at a second carrier frequency different from the first carrier frequency, respectively, andfurther circuitry, the further circuitry being operable to receive an intermediate frequency (IF) common to each mode of operation and further downconvert the IF common to each mode into a further signal and to supply the further signal to further circuitry.
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Accused Products
Abstract
A method and apparatus for receiving a radio frequency signal and a method and apparatus for transmitting a modulation signal in a multiple channel radio system. The method for receiving the radio frequency signal involves mixing the radio frequency signal with a demodulating signal, tunable in frequency steps greater than the channel spacing of the multiple channel radio system to facilitate rapid frequency adjustments. The resultant intermediate signal is then mixed with another demodulating signal, tunable in relatively smaller frequency steps in order to select the channel containing the radio frequency signal.
43 Citations
36 Claims
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1. A dual-mode receiver operable to receive signals in a first mode having an associated first channel spacing, and to receive signals in a second mode having an associated second channel spacing smaller than the first channel spacing, comprising:
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first and second front-end RF stages for receiving a signal transmitted in the first mode at a first carrier frequency and the second mode at a second carrier frequency different from the first carrier frequency, respectively, and further circuitry, the further circuitry being operable to receive an intermediate frequency (IF) common to each mode of operation and further downconvert the IF common to each mode into a further signal and to supply the further signal to further circuitry. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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15. A dual-mode transmitter operable to transmit signals in a first mode having an associated first channel spacing, and to transmit signals in a second mode having an associated second channel spacing smaller than the first channel spacing, comprising:
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first and second terminal RF stages for transmitting a signal in the first mode at a first carrier frequency and in the second mode at a second carrier frequency different from the first carrier frequency, respectively, and further circuitry, the further circuitry being operable to upconvert a received signal into an intermediate frequency (IF) common to each mode of operation and to supply the IF common to each mode to the first and the second terminal RE stages. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 36)
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Specification