Multicarrier communication system and method for peak power control
AssigneeMotorola, Inc.
InventorsAlan Jones, Timothy Alan Wilkinson
Life of this patent
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Abstract
A communication device for simultaneously transmitting information on multiple sub-channels encodes information for each of the multiple sub-channels with a coding scheme to produce channel encoded information. A mask vector derived from a redundancy in the coding scheme, encodes the channel encoded information to transform the channel encoded information into codewords having pairwise Euclidean distance properties identical to those of the channel encoded information, Modulation of the sub-channels in accordance with the codewords in a modulator then produces a composite signal envelope having a peak-to-mean error power ratio (PMEPR) reduced relative to a PMEPR for correspondingly modulated channel encoded information.
Claims23
A communication device for simultaneously transmitting information on multiple sub-channels, the communication device comprising:
- an encoder circuit to encode the information for each of the multiple subchannels with a first coding scheme, said first coding scheme produced from a transformation of a second coding scheme, the transformation derived from redundancy in the second coding scheme, said first coding scheme producing codewords having pairwise Euclidean distance properties corresponding to those of the same information encoded by said second coding scheme alone, and said transformation being selected so that a modulated composite signal envelope derived from said codewords has a peak-to-mean envelope power ratio (PMEPR) reduced relative to a PMEPR for correspondingly modulated information encoded by said second coding scheme alone;
- and
- a modulator bank operatively coupled to said encoder circuit for modulating said sub-channels in accordance with said codewords to produce a composite signal envelope.
A method of simultaneously transmitting information on multiple channels comprising the steps of:
- encoding the information for each of the multiple sub-channels with a first coding scheme, said first coding scheme incorporating a second coding scheme and a transformation derived from redundancy in the second coding scheme, said first coding scheme producing codewords having pairwise Euclidean distance properties corresponding to those of the same information encoded by said second coding scheme alone, and said transformation being selected so that a modulated composite signal envelope derived from said codewords has a peak-to-mean envelope power ratio (PMEPR) reduced relative to a PMEPR for correspondingly modulated information encoded by said second coding scheme alone;
- and
- modulating the sub-channels in accordance with said codewords to produce a composite signal envelope.
A communication device for simultaneously transmitting information on multiple sub-channels, the communication device comprising:
- an encoder circuit to encode according to a first coding scheme the information for transmission in multiple sub-channels, said encoder circuit producing codewords encoded according to said first coding scheme from a transformation of data encoded according to a second coding scheme, said transformation comprising a transformation vector derived from a redundancy in said second coding scheme, said transformation produced codewords having pairwise Euclidean distance properties corresponding to those of the same information encoded by said second coding scheme alone, and said transformation vector being selected so that a modulated composite signal envelope derived from said codewords has a peak-to-mean envelope power ratio (PMEPR) reduced relative to a PMEPR for correspondingly modulated information encoded by said second coding scheme alone;
- and
- a modulator bank operatively coupled to said encoder circuit for modulating said sub-channels in accordance with said codewords to produce a composite signal envelope.
Dependencies are inferred from the claim text.