QAM signal decoding
First Claim
Patent Images
1. A demodulator for recovering a transmitted symbol represented by a received quadrature amplitude modulation (QAM) signal, the demodulator comprising:
- a QAM-decoding block operable tomap a received signal vector onto a constellation so as to yield a first symbol, andidentify a next-most probable second symbol based upon the signal vector; and
a selection unit operable to select, among the first and second symbols, the one having a lower error content as corresponding to the transmitted symbol;
whereinthe QAM-decoding block includesat least two decoders operable to produce at least first and second bit streams corresponding to the first and second symbols, respectively; and
the selection unit includesat least two error-checking units operable upon the first and second bit streams; and
logic to select the one of the first and second bit streams having the lower error content as corresponding to the transmitted symbol.
1 Assignment
0 Petitions
Accused Products
Abstract
A demodulator recovers a transmitted symbol represented by a received quadrature amplitude modulation (QAM) signal. Such a demodulator may include: a QAM-decoding block operable to map a received signal vector onto a constellation so as to yield a first symbol, and identify a next-most probable second symbol based upon the signal vector; and a selection unit operable to select, among the first and second symbols, the one having the lower error content as corresponding to the transmitted symbol. A corresponding method may include similar steps.
-
Citations
12 Claims
-
1. A demodulator for recovering a transmitted symbol represented by a received quadrature amplitude modulation (QAM) signal, the demodulator comprising:
-
a QAM-decoding block operable to map a received signal vector onto a constellation so as to yield a first symbol, and identify a next-most probable second symbol based upon the signal vector; and a selection unit operable to select, among the first and second symbols, the one having a lower error content as corresponding to the transmitted symbol;
whereinthe QAM-decoding block includes at least two decoders operable to produce at least first and second bit streams corresponding to the first and second symbols, respectively; and the selection unit includes at least two error-checking units operable upon the first and second bit streams; and logic to select the one of the first and second bit streams having the lower error content as corresponding to the transmitted symbol. - View Dependent Claims (2, 3, 4)
-
-
5. A demodulator for recovering a transmitted symbol represented by a received quadrature amplitude modulation (QAM) signal, the demodulator comprising:
-
a QAM-decoding block operable to map a received signal vector onto a constellation so as to yield a first symbol, and identify a next-most probable second symbol based upon the signal vector; and a selection unit operable to select, among the first and second symbols, the one having a lower error content as corresponding to the transmitted symbol;
wherein the QAM-decoding block is further operable toevaluate whether a sub-channel to which the first symbol corresponds is extra-noisy; determine, if the sub-channel is extra-noisy, whether the signal vector is mapped to an overlap region; proceed, if the signal vector is mapped to an overlap region, to the identification and selection. - View Dependent Claims (6, 7, 8)
-
-
9. A method of recovering a transmitted symbol represented by a received quadrature amplitude modulation (QAM) signal, the method comprising:
-
mapping, by a decoder, a received signal vector onto a constellation to yield a first symbol; identifying a next-most probable second symbol based upon the signal vector; selecting, by a selector, among the first and second symbols, the one having a lower error content as corresponding to the transmitted symbol; receiving an indication of whether a sub-channel to which the first symbol corresponds is extra-noisy; determining, if the sub-channel is extra-noisy, whether the mapping step has mapped the signal vector to an overlap region; and proceeding, if the signal vector is mapped to an overlap region, to the identifying and selecting steps. - View Dependent Claims (10, 11)
-
-
12. A demodulator comprising:
-
a decoder configured to, map a received signal vector onto a constellation to yield a first symbol, receive an indication of whether a sub-channel to which the first symbol corresponds is extra-noisy, determine, if the sub-channel is extra-noisy, whether the signal vector has been mapped to an overlap region, and identify a next-most probable second symbol based upon the signal vector; and a selector configured to, select, among the first and second symbols, the one having a lower error content as corresponding to the transmitted symbol.
-
Specification