Adaptive trellis coding enabling and disabling in discrete multitone data communications
AssigneeAdtran, Inc.
InventorArlynn W. Wilson
Life of this patent
Estimating the term…
Abstract
In a transmitter, first and second sets of discrete multitone (DMT) sub-carrier signals or tones are identified. First and second bit groups of a payload data frame corresponding to the first and second sets of tones are selected. The first bit group is then trellis encoded. The second bit group is not trellis encoded. The first trellis coded tone group and the second bit group are then constellation mapped to produce a DMT symbol for transmission. A receiver may use an estimate of signal-to-noise ratio (SNR) of each tone to determine whether to select the tone for inclusion in the first or second set of tones. The receiver may provide the transmitter with information indicating whether a tone is included the first or second set of tones.
Claims30
A method for discrete multitone (DMT) data transmission, comprising:
- identifying a first set of tones and a second set of tones;
- selecting a first bit group comprising a first plurality of bits of a payload data frame, the first bit group corresponding to the first set of tones;
- selecting a second bit group comprising a second plurality of bits of the payload frame, the second bit group corresponding to the second set of tones;
- trellis encoding the first plurality of bits to produce a first trellis coded tone group;
- constellation mapping the first trellis coded tone group and the second bit group to produce a DMT symbol;
- and
- transmitting the DMT symbol via a communication channel.
A method for discrete multitone (DMT) data reception, comprising:
- receiving a DMT symbol via a communication channel;
- constellation de-mapping the DMT symbol to produce a first plurality of bits defining a first bit group and a second plurality of bits defining a second bit group, the first bit group corresponding to a first set of tones, the second bit group corresponding to a second set of tones;
- trellis decoding the first plurality of bits to produce a plurality of trellis decoder output bits;
- combining the trellis decoder output bits and the second plurality of bits to produce a payload data frame;
- estimating a signal-to-noise ratio (SNR) of each of a plurality of tones;
- selecting the first set of tones and the second set of tones from the plurality of tones by comparing the SNR of each of the plurality of tones with a threshold;
- and
- transmitting a message via a messaging channel identifying a tone whether a tone is included in one of the first set of tones and the second set of tones.
A transmitter system for discrete multitone (DMT) data communication, comprising:
- a memory configured to store information indicating whether each of a plurality of tones is included in one of a first set of tones and a second set of tones;
- a data frame buffer configured to buffer a payload data frame;
- a bit extractor configured to select a first bit group comprising a first plurality of bits of the data frame buffer and a second bit group comprising a second plurality of bits of the data frame buffer, the first bit group corresponding to the first set of tones, the second bit group corresponding to the second set of tones;
- a trellis encoder configured to encode the first plurality of bits to produce a first trellis coded tone group;
- and
- a constellation mapper configured to produce a DMT symbol in response to the first trellis coded tone group and the second bit group for transmission via a communication channel.
A receiver system for discrete multitone (DMT) data communication, comprising:
- a constellation de-mapper configured to de-map a DMT symbol received via a communication channel to produce a first plurality of bits defining a first bit group and a second plurality of bits defining a second bit group, the first bit group corresponding to a first set of tones, the second bit group corresponding to a second set of tones;
- a trellis decoder configured to trellis decode the first plurality of bits to produce a plurality of trellis decoder output bits;
- a combiner configured to combine the trellis decoder output bits and the second plurality of bits to produce a payload data frame;
- a signal-to-noise ratio (SNR) estimator configured to estimate a signal-to-noise ratio (SNR) of each of a plurality of tones;
- a tone selector configured to select the first set of tones and the second set of tones from the plurality of tones by comparing the SNR of each of the plurality of tones with a threshold;
- and
- a messaging system configured to transmit a message via a messaging channel identifying a tone whether a tone is included in one of the first set of tones and the second set of tones.
Dependencies are inferred from the claim text.