Method and system for signal detection using a reduced transmitter constellation
The present invention relates to a method, typically deployed on receivers deployed, for detecting a transmitted signal from a transmitter constellation by quantizing an altered signal to obtain a reduced constellation from the transmitter constellation ( 205 ), and then performing a maximum-likelihood detection scheme on the reduced constellation to obtain the transmitted signal ( 210 ). A system ( 120, 125 ) to perform the detection is also disclosed.
1 . A method of detecting a transmitted signal from a transmitter constellation, the method comprising:
processing the transmitted signal to produce an altered signal;
quantizing the altered signal to obtain a reduced constellation from the transmitter constellation based on a predetermined procedure; and
performing a maximum-likelihood detection scheme on the reduced constellation to obtain the transmitted signal.
2 . The method of claim 1 , where the altered signal is obtained using at least one of a zero forcing (ZF) detection scheme and a minimum mean square error (MMSE) detection scheme.
3 . The method of claim 1 , wherein the altered signal comprises a product of a received signal matrix corresponding to the transmitted signal and a transformation matrix based on a transmission channel.
4 . The method of claim 3 , wherein the predetermined procedure is based on a modulation scheme.
5 . The method of claim 4 , wherein the predetermined procedure comprises:
performing at least one of a floor and ceiling operation on the altered signal to obtain the reduced constellation for a QAM modulation scheme.
6 . The method of claim 4 , wherein the predetermined procedure comprises:
performing an angle operation on the altered signal to obtain the reduced constellation for a PSK modulation scheme, the angle operation computing at least one nearest angle to the altered signal.
7 . The method of claim 4 , wherein the predetermined procedure comprises:
multiplying the altered signal with a transformation of a rotation matrix for a rotated QAM scheme to obtain a rotated altered signal, the rotation matrix corresponding to a rotated QAM; and
performing at least one of a floor and ceiling operation on the rotated altered signal to obtain the reduced constellation for the rotated QAM scheme.
8 . The method of claim 4 , wherein the modulation scheme comprises at least one of a quadrature amplitude modulation (QAM) scheme, rotated QAM scheme, phase-shift keying (PSK) scheme and a lattice constellation modulation scheme.
9 . A receiver to detect a transmitted signal from a transmitter constellation, the receiver comprising:
a processor;
a memory operatively coupled to the processor and configured to store instructions that cause the processor to:
process the transmitted signal to produce an altered signal;
quantize the altered signal to obtain a reduced constellation from the transmitter constellation based on a predetermined procedure; and
perform a maximum-likelihood detection scheme on the reduced constellation to obtain the transmitted signal.
10 . The receiver of claim 9 , where the altered signal is obtained using at least one of a zero forcing (ZF) detection scheme and a minimum mean square error (MMSE) detection scheme.
11 . The receiver of claim 9 , wherein the altered signal comprises a product of a received signal matrix corresponding to the transmitted signal and a transformation matrix based on a transmission channel.
12 . The receiver of claim 11 , wherein the predetermined procedure is based on a modulation scheme.
13 . The receiver of claim 12 , wherein the modulation scheme comprises at least one of a quadrature amplitude modulation (QAM) scheme, rotated QAM scheme, phase-shift key (PSK) scheme.
14 . The receiver of claim 9 is a part of at least one of a mobile device, a personal digital assistant and a laptop.
15 . A system to detect a transmitted signal from a transmitter constellation, the system comprising:
a processing module for transforming the transmitted signal to produce an altered signal;
a quantizing module for quantizing the altered signal to obtain a reduced constellation from the transmitter constellation based on a predetermined procedure; and
an ML-detection module for performing a maximum-likelihood detection scheme on the reduced constellation to obtain the transmitted signal.
16 . The system of claim 15 , wherein the predetermined procedure is based on a modulation scheme.
17 . The system of claim 16 , wherein the quantizing module is configured to perform at least one of a floor and ceiling operation on the altered signal to obtain the reduced constellation for a QAM modulation scheme.
18 . The system of claim 16 , wherein the quantizing module is configured to perform an angle operation on the altered signal to obtain the reduced constellation for a PSK modulation scheme, the angle operation computing at least one nearest angle to the altered signal.
19 . The system of claim 16 , wherein the quantizing module is configured to multiply the altered signal with a transformation of a rotation matrix for a rotated QAM scheme to obtain a rotated altered signal, the rotation matrix corresponding to a rotated QAM and performing at least one of a floor and ceiling operation on the rotated altered signal to obtain the reduced constellation for the rotated QAM scheme.
20 . The system of claim 16 , wherein the modulation scheme comprises at least one of a quadrature amplitude modulation (QAM) scheme, rotated QAM scheme, phase-shift key (PSK) scheme.
21 . The system of claim 15 , wherein the system is part of a receiver system.