Receiver for estimating signal magnitude, noise power, and signal-to-noise ratio of received signals

Abstract

A method and apparatus for estimating attributes of a received signal that includes a plurality of transmitted signals are provided. The amplitude of the received signal is estimated by performing a method of demodulation based on known signal information. The amplitude of an M-ary quadrature amplitude modulated signal is estimated based upon known or ascertainable phase information regarding a plurality of transmitted symbols. The amplitude of a q-ary amplitude shift keyeing signal is estimated based upon known or ascertainable magnitude information regarding a plurality of transmitted symbols. Statistical information is also used for amplitude estimation.

1 . A method for use in wireless communication, the method comprising:
 estimating an amplitude of a received signal that includes a plurality of transmitted symbols by:
 performing ascertainable phase demodulation, on a condition that the received signal is an M-ary quadrature amplitude demodulation (M-QAM) signal and phase information of the plurality of transmitted symbols is known; 
 performing ascertainable magnitude demodulation, on a condition that the received signal is a q-ary amplitude shift keyeing (q-ASK) signal and magnitude information of the plurality of transmitted symbols is known; and 
 performing absolute value demodulation, on a condition that magnitude information and phase information regarding the plurality of transmitted symbols is unknown. 
   
   
   
       2 . The method of  claim 1 , wherein the performing ascertainable phase demodulation includes:
 recovering a plurality of received symbols corresponding to the plurality of transmitted symbols;   generating a plurality of products based on the plurality of received symbols;   summing the plurality of products;   determining the real part of the sum of products;   generating a magnitude value by summing the absolute values of the plurality of transmitted symbols; and   generating the estimated amplitude of the received signal by dividing the real part of the sum of products by the magnitude value.   
   
   
       3 . The method of  claim 2 , wherein the generating the plurality of products includes multiplying each of the plurality of received symbols by a phase of a corresponding transmitted symbol. 
   
   
       4 . The method of  claim 1 , wherein the performing ascertainable magnitude demodulation includes:
 recovering a plurality of received samples corresponding to the plurality of transmitted symbols,   generating a plurality of products by multiplying each sample in the plurality of samples by a corresponding sign,   summing the plurality of products to generate a first sum,   summing the absolute values of the plurality of transmitted symbols to generate a second sum, and   generating the estimated amplitude of the received signal by dividing the first sum by the second sum.   
   
   
       5 . The method of  claim 1 , wherein the performing absolute value demodulation includes:
 recovering a plurality of received samples corresponding to the plurality of transmitted symbols,   determining the absolute values of the plurality of received samples,   summing the absolute values to generate a first sum,   determining a mean of the absolute values of the amplitudes of the plurality of transmitted symbols,   multiplying the mean of the absolute values by the number of symbols in the plurality of transmitted symbols to generate a product, and   generating the estimated amplitude of the received signal by dividing the first sum by the product.   
   
   
       6 . A wireless transmit/receive unit (WTRU) comprising:
 a receiver configured to receive a signal that includes a plurality of transmitted symbols; and   a processor configured to estimate an amplitude of the received signal by:
 performing ascertainable phase demodulation, on a condition that the received signal is an M-ary quadrature amplitude demodulation (M-QAM) signal and phase information of the plurality of transmitted symbols is known; 
 performing ascertainable magnitude demodulation, on a condition that the received signal is a q-ary amplitude shift keyeing (q-ASK) signal and magnitude information of the plurality of transmitted symbols is known; and 
 performing absolute value demodulation, on a condition that magnitude information and phase information regarding the plurality of transmitted symbols is unknown. 
   
   
   
       7 . The WTRU of  claim 6 , wherein the processor is configured to perform ascertainable phase demodulation by:
 recovering a plurality of received symbols corresponding to the plurality of transmitted symbols;   generating a plurality of products based on the plurality of received symbols;   summing the plurality of products;   determining the real part of the sum of products;   generating a magnitude value by summing the absolute values of the plurality of transmitted symbols; and   generating the estimated amplitude of the received signal by dividing the real part of the sum of products by the magnitude value.   
   
   
       8 . The WTRU of  claim 7 , wherein the processor is configured to generate the plurality of products by multiplying each of the plurality of received symbols by a phase of a corresponding transmitted symbol. 
   
   
       9 . The WTRU of  claim 6 , wherein the processor is configured to perform ascertainable magnitude demodulation by:
 recovering a plurality of received samples corresponding to the plurality of transmitted symbols,   generating a plurality of products by multiplying each sample in the plurality of samples by a corresponding sign,   summing the plurality of products to generate a first sum,   summing the absolute values of the plurality of transmitted symbols to generate a second sum, and   generating the estimated amplitude of the received signal by dividing the first sum by the second sum.   
   
   
       10 . The WTRU of  claim 6 , wherein the processor is configured to perform absolute value demodulation by:
 recovering a plurality of received samples corresponding to the plurality of transmitted symbols,   determining the absolute values of the plurality of received samples,   summing the absolute values to generate a first sum,   determining a mean of the absolute values of the amplitudes of the plurality of transmitted symbols,   multiplying the mean of the absolute values by the number of symbols in the plurality of transmitted symbols to generate a product, and   generating the estimated amplitude of the received signal by dividing the first sum by the product.   
   
   
       11 . A base station comprising:
 a receiver configured to receive a signal that includes a plurality of transmitted symbols; and   a processor configured to estimate an amplitude of the received signal by:
 performing ascertainable phase demodulation, on a condition that the received signal is an M-ary quadrature amplitude demodulation (M-QAM) signal and phase information of the plurality of transmitted symbols is known; 
 performing ascertainable magnitude demodulation, on a condition that the received signal is a q-ary amplitude shift keyeing (q-ASK) signal and magnitude information of the plurality of transmitted symbols is known; and 
 performing absolute value demodulation, on a condition that magnitude information and phase information regarding the plurality of transmitted symbols is unknown. 
   
   
   
       12 . The base station of  claim 11 , wherein the processor is configured to perform ascertainable phase demodulation by:
 recovering a plurality of received symbols corresponding to the plurality of transmitted symbols;   generating a plurality of products based on the plurality of received symbols;   summing the plurality of products;   determining the real part of the sum of products;   generating a magnitude value by summing the absolute values of the plurality of transmitted symbols; and   generating the estimated amplitude of the received signal by dividing the real part of the sum of products by the magnitude value.   
   
   
       13 . The base station of  claim 12 , wherein the processor is configured to generate the plurality of products by multiplying each of the plurality of received symbols by a phase of a corresponding transmitted symbol. 
   
   
       14 . The base station of  claim 11 , wherein the processor is configured to perform ascertainable magnitude demodulation by:
 recovering a plurality of received samples corresponding to the plurality of transmitted symbols,   generating a plurality of products by multiplying each sample in the plurality of samples by a corresponding sign,   summing the plurality of products to generate a first sum,   summing the absolute values of the plurality of transmitted symbols to generate a second sum, and   generating the estimated amplitude of the received signal by dividing the first sum by the second sum.   
   
   
       15 . The base station of  claim 11 , wherein the processor is configured to perform absolute value demodulation by:
 recovering a plurality of received samples corresponding to the plurality of transmitted symbols,   determining the absolute values of the plurality of received samples,   summing the absolute values to generate a first sum,   determining a mean of the absolute values of the amplitudes of the plurality of transmitted symbols,   multiplying the mean of the absolute values by the number of symbols in the plurality of transmitted symbols to generate a product, and   generating the estimated amplitude of the received signal by dividing the first sum by the product.