Radio receiver for use in the reception of digital multiplexing signals
First Claim
1. A digital multiplexing radio receiver comprising:
- first means for generating a carrier frequency signal;
second means for demodulating a received multi-level orthogonal amplitude signal with the carrier frequency signal output from the first means and outputting Ich and Qch demodulated orthogonal signals;
third means operatively connected to the second means for amplifying the Ich and Qch demodulated orthogonal signals and outputting Ich and Qch amplified signals;
fourth means operatively connected to the third means for adaptively equalizing the Ich and Qch amplified signals and outputting Ich and Qch adaptively-equalized data;
fifth means operatively connected to the first means and the fourth means for supplying a first control signal to the first means to make the frequency of the carrier frequency signal the same as that of the received multi-level orthogonal amplitude signal; and
sixth means operatively connected to the third means and the fourth means for generating and outputting a second control signal to the third means to amplify the Ich and Qch demodulated signals to a predetermined level, the second control signal being generated based on the Ich and Qch adaptively-equalized data output from the fourth means, of the multi-level orthogonal amplitude signal existing in a signal point area on a phase plane of Ich and Qch orthogonal coordinates in the case where the Ich and Qch demodulated orthogonal signal is synchronized with the carrier frequency signal, and of the multi-level orthogonal amplitude signal existing in a first specified area other than the signal point area on a phase plane of Ich and Qch orthogonal coordinates in the case where the Ich and Qch demodulated orthogonal signal is not synchronized with the carrier frequency signal.
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Accused Products
Abstract
In the case where a received multi-level orthogonal amplitude signal is not synchronized with a local carrier frequency signal, a digital multiplexing radio receiver recognizes that an adaptively-equalized data exist in a specified area on the phase plane of Ich and Qch orthogonal coordinates. The receiver controls an operation of amplifying Ich and Qch demodulated signals to a fixed level, based on the data of which exist in the specified area. Similarly, the receiver controls a phase of the local carrier frequency signal based on the data of existing in the specified area, and controls tap coefficients of an adaptive transversal filter which equalizes the received multi-level orthogonal amplitude signal. In the specified area, a distance between signal points of multi-level orthogonal amplitude signal is large so that influence caused by a phase rotation is small. Accordingly, the digital multiplexing radio receiver can rapidly and stably return to a synchronous mode.
40 Citations
12 Claims
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1. A digital multiplexing radio receiver comprising:
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first means for generating a carrier frequency signal; second means for demodulating a received multi-level orthogonal amplitude signal with the carrier frequency signal output from the first means and outputting Ich and Qch demodulated orthogonal signals; third means operatively connected to the second means for amplifying the Ich and Qch demodulated orthogonal signals and outputting Ich and Qch amplified signals; fourth means operatively connected to the third means for adaptively equalizing the Ich and Qch amplified signals and outputting Ich and Qch adaptively-equalized data; fifth means operatively connected to the first means and the fourth means for supplying a first control signal to the first means to make the frequency of the carrier frequency signal the same as that of the received multi-level orthogonal amplitude signal; and sixth means operatively connected to the third means and the fourth means for generating and outputting a second control signal to the third means to amplify the Ich and Qch demodulated signals to a predetermined level, the second control signal being generated based on the Ich and Qch adaptively-equalized data output from the fourth means, of the multi-level orthogonal amplitude signal existing in a signal point area on a phase plane of Ich and Qch orthogonal coordinates in the case where the Ich and Qch demodulated orthogonal signal is synchronized with the carrier frequency signal, and of the multi-level orthogonal amplitude signal existing in a first specified area other than the signal point area on a phase plane of Ich and Qch orthogonal coordinates in the case where the Ich and Qch demodulated orthogonal signal is not synchronized with the carrier frequency signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A digital multiplexing radio receiver comprising:
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a means for generating a local carrier frequency signal; a means for demodulating a received multi-level orthogonal amplitude signal to Qch and Ich demodulated orthogonal signals with the local carrier frequency signal; a means operatively connected to the demodulating means for amplifying the Qch and Ich demodulated orthogonal signals and outputting Qch and Ich amplified signals; an adaptive transversal filter means operatively connected to the amplifying means for adaptively equalizing the Qch and Ich amplified signals and outputting Qch and Ich adaptively-equalized data; a means for obtaining an error signal of a signal point of the multi-level orthogonal amplitude signal; a means for obtaining an EXOR between a polarity bit of an adaptively-equalized data outputted from the adaptive transversal filter means and a first bit of the error signal; and a means for determining a direction of phase control of the local carrier signal according to the relation between the obtained EXOR and a fixed EXOR corresponding to each signal point. - View Dependent Claims (10, 11, 12)
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Specification