Methodology and method and apparatus for signaling with capacity optimized constellations
First Claim
1. A digital communication system, comprising:
- a transmitter configured to transmit signals to a receiver via a communication channel;
wherein the transmitter, comprises;
a coder configured to receive user bits and output encoded bits at an expanded output encoded bit rate;
a mapper configured to map said encoded bits to symbols in a first symbol constellation, wherein the first symbol constellation comprises a set of non-uniformly spaced points;
a modulator configured to generate a signal for transmission via the communication channel using symbols generated by the mapper;
wherein the receiver, comprises;
a demodulator configured to demodulate the received signal via the communication channel;
a demapper configured to estimate likelihoods from the demodulated signal;
a decoder that is configured to estimate decoded bits from the likelihoods generated by the demapper;
wherein the first symbol constellation is a capacity optimized non-uniformly spaced symbol constellation that provides a given capacity at a reduced signal-to-noise ratio compared to a signal constellation that maximizes dmin; and
wherein the transmitter and the receiver adapt from using the first symbol constellation to a second capacity optimized non-uniformly spaced symbol constellation in response to channel conditions.
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Accused Products
Abstract
Communication systems are described that use geometrically shaped constellations that have increased capacity compared to conventional constellations operating within a similar SNR band. In several embodiments, the geometrically shaped is optimized based upon a capacity measure such as parallel decoding capacity or joint capacity. In many embodiments, a capacity optimized geometrically shaped constellation can be used to replace a conventional constellation as part of a firmware upgrade to transmitters and receivers within a communication system. In a number of embodiments, the geometrically shaped constellation is optimized for an Additive White Gaussian Noise channel or a fading channel.
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Citations
45 Claims
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1. A digital communication system, comprising:
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a transmitter configured to transmit signals to a receiver via a communication channel; wherein the transmitter, comprises; a coder configured to receive user bits and output encoded bits at an expanded output encoded bit rate; a mapper configured to map said encoded bits to symbols in a first symbol constellation, wherein the first symbol constellation comprises a set of non-uniformly spaced points; a modulator configured to generate a signal for transmission via the communication channel using symbols generated by the mapper; wherein the receiver, comprises; a demodulator configured to demodulate the received signal via the communication channel; a demapper configured to estimate likelihoods from the demodulated signal; a decoder that is configured to estimate decoded bits from the likelihoods generated by the demapper; wherein the first symbol constellation is a capacity optimized non-uniformly spaced symbol constellation that provides a given capacity at a reduced signal-to-noise ratio compared to a signal constellation that maximizes dmin; and wherein the transmitter and the receiver adapt from using the first symbol constellation to a second capacity optimized non-uniformly spaced symbol constellation in response to channel conditions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A digital communication system, comprising:
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a transmitter configured to transmit signals to a receiver via a communication channel; wherein the transmitter, comprises; a coder configured to receive user bits and output encoded bits at an expanded output encoded bit rate; a mapper configured to map said encoded bits to symbols in a first symbol constellation, wherein the first symbol constellation comprises a set of non-uniformly spaced points; a modulator configured to generate a signal for transmission via the communication channel using symbols generated by the mapper; wherein the first symbol constellation is a capacity optimized non-uniformly spaced symbol constellation that provides a given capacity at a reduced signal-to-noise ratio compared to a signal constellation that maximizes dmin; and wherein the transmitter adapts from using the first symbol constellation to a second capacity optimized non-uniformly spaced symbol constellation in response to channel conditions. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A digital communication system, comprising:
a receiver configured to receive a signal via a communication channel, wherein the receiver, comprises; a demodulator configured to demodulate the received signal via the communication channel; a demapper configured to estimate likelihoods from the demodulated signal; a decoder that is configured to estimate decoded bits from the likelihoods generated by the demapper, using a first symbol constellation; wherein the first symbol constellation is a capacity optimized non-uniformly spaced symbol constellation that provides a given capacity at a reduced signal-to-noise ratio compared to a signal constellation that maximizes dmin; and wherein the receiver adapts from using the first symbol constellation to a second capacity optimized non-uniformly spaced symbol constellation in response to channel conditions. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45)
Specification