Satellite receiver

Abstract

Systems and techniques for receiving a satellite signal wherein the signal is demodulated and iterative decoded. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

1 . A method of correlation, comprising: 
 (a) computing a difference in phase between adjacent symbols in a first symbol sequence to produce a plurality of differential symbols; and    (b) correlating the differential symbols with a second symbol sequence.    
   
   
       2 . The method of  claim 1  wherein the difference computation comprises coherently multiplying each of the adjacent symbols of the first symbol sequence to produce the differential symbols.  
   
   
       3 . The method of  claim 1  wherein the second symbol sequence corresponds to the differential symbols.  
   
   
       4 . The method of  claim 1  wherein step (b) comprises convolving each of the differential symbols with one of second symbols in the second symbol sequence to produce a plurality of convolved values.  
   
   
       5 . The method of  claim 4  wherein step (b) further comprises summing the convolved values.  
   
   
       6 . The method of  claim 1  wherein the difference computation comprises coherently multiplying each adjacent symbol of the first symbol sequence to produce the differential symbols, and step (b) comprises convolving each of the differential symbols with one of second symbols in the second symbol sequence to produce a plurality of convolved values and summing the convolved values, the second symbol sequence corresponding to the differential symbols.  
   
   
       7 . The method of  claim 1  further comprising receiving a signal having the first symbol sequence therein.  
   
   
       8 . A differential correlator, comprising: 
 (a) a differential symbol generator configured to compute a difference in phase between between adjacent symbols in a first symbol sequence to produce a plurality of differential symbols; and    (b) a correlator configured to correlate the differential symbols with a second symbol sequence.    
   
   
       9 . The differential correlator of  claim 8  wherein the differential symbol generator comprises a multiplier configured to coherently multiply each of the adjacent symbols of the first symbol sequence to produce the differential symbols.  
   
   
       10 . The differential correlator of  claim 9  wherein the differential symbol generator further comprises a delay and conjugate element configured to sequentially receive the first symbol sequence, and wherein the multiplier is further configured to multiply each delayed and conjugated symbol, resulting from the corresponding delay and conjugate element, with the succeeding symbol of the first symbol sequence.  
   
   
       11 . The differential correlator of  claim 8  wherein the correlator comprises a multiplier configured to convolve the differential symbols with the second symbol sequence to produce a plurality of convolved values, and an adder configured to sum the plurality of convolved values.  
   
   
       12 . The differential correlator of  claim 11  wherein the correlator further comprises a plurality of serial delay elements configured to sequentially receive the differential symbols, each of the serial delay elements providing one of the differential symbols to the multiplier.  
   
   
       13 . The differential correlator of  claim 12  wherein the multiplier comprises a plurality of multipliers each configured to receive one of the differential symbols respectively from the delay elements.  
   
   
       14 . The differential correlator of  claim 13  wherein the correlator is further configured to provide one of the symbols of the second symbol sequence to each of the multipliers.  
   
   
       15 . The differential correlator of  claim 8  wherein the correlator further comprises a storage medium configured to store the second symbol sequence, the second symbol sequence corresponding to the differential symbols.  
   
   
       16 . A differential correlator, comprising: 
 (a) computing means for computing a difference in phase between between adjacent symbols of a first symbol sequence to produce a plurality of differential symbols; and    (b) correlation means for correlating the differential symbols with a second symbol sequence.    
   
   
       17 . The differential correlator of  claim 16  wherein the computing means comprises multiplier means for coherently multiplying each of the adjacent symbols of the first symbol sequence to produce the differential symbols.  
   
   
       18 . The differential correlator of  claim 16  wherein the correlation means comprises convolution means for convolving the differential symbols with the second symbol sequence to produce a plurality of convolved values.  
   
   
       19 . The differential correlator of  claim 18  wherein the convolution means comprises a multiplier.  
   
   
       20 . The differential correlator of  claim 18  wherein the correlation means further comprises summer means for summing the plurality of convolved values.  
   
   
       21 . The differential correlator of  claim 20  wherein the summer means comprises an adder.  
   
   
       22 . A method of correlating a first symbol sequence with a second symbol sequence, comprising: 
 (a) sequentially convolving each symbol of the first symbol sequence with one of the symbols of the second symbol sequence to produce a plurality of sequential convolved values; and    (b) accumulating the convolved values.    
   
   
       23 . The method of  claim 22  wherein step (a) comprises sequentially multiplying each of the symbols of the first symbol sequence with a respective symbol from the second symbol sequence.  
   
   
       24 . The method of  claim 22  wherein the second symbol sequence corresponds to the first symbol sequence.  
   
   
       25 . The method of  claim 22  wherein step (a) comprises providing each of the symbols of the first symbol sequence to a multiplier with a corresponding symbol from the second symbol sequence.  
   
   
       26 . The method of  claim 25  further comprising performing a symbol count of the first symbol sequence provided to the multiplier, a corresponding one of the symbols from the second symbol sequence provided to the multiplier being a function of the symbol count.  
   
   
       27 . The method of  claim 22  further comprising receiving a signal having the first symbol sequence therein.  
   
   
       28 . The method of  claim 27  wherein the received signal comprises a training portion having the first symbol sequence and a data portion having data symbols.  
   
   
       29 . The method of  claim 28  wherein step (a) comprises providing each of the symbols of the first symbol sequence to a multiplier with a corresponding one of the symbols from the second symbol sequence, the method further comprising performing a symbol count of the first symbol sequence provided to the multiplier, the corresponding one of the symbols from the second symbol sequence provided to the multiplier being a function of the symbol count.  
   
   
       30 . A serial correlator, comprising: 
 (a) a multiplier configured to sequentially convolve each symbol of a first symbol sequence with a symbol from a second symbol sequence to produce a plurality of convolved values; and    (b) an accumulator configured to accumulate the sequentially convolved values.    
   
   
       31 . The serial correlator of  claim 30  further comprising a storage medium configured to store the second symbol sequence, the second symbol sequence corresponding to the first symbol sequence.  
   
   
       32 . The serial correlator of  claim 31  further comprising a processor configured to determine the sequence in which the symbols of the second symbol sequence from the storage medium are provided to the multiplier.  
   
   
       33 . The serial correlator of  claim 32  further comprising a symbol counter configured to count the symbols from the first symbol sequence sequentially provided to the multiplier, the processor determining the sequence in which the symbols of the second symbol sequence are provided to the multiplier as a function of the symbol count.  
   
   
       34 . A serial correlator, comprising: 
 (a) convolution means for sequentially convolving each symbol of a first symbol sequence with a symbol from a second symbol sequence to produce a plurality of convolved values; and    (b) accumulation means for accumulating the sequentially convolved values.    
   
   
       35 . The serial correlator of  claim 34  further comprising means for storing the second symbol sequence, the second symbol sequence corresponding to the first symbol sequence.  
   
   
       36 . The serial correlator of  claim 34  further comprising means for determining the symbol from the second symbol sequence to be convolved with each of the symbols from the first symbol sequence.  
   
   
       37 . The serial correlator of  claim 34  further comprising means for performing a symbol count from the first symbol sequence sequentially provided to the convolution means, and means for determining the symbol of the second symbol sequence to be convolved with each of the symbols from the first symbol sequence as a function of the symbol count.  
   
   
       38 . The serial correlator of  claim 34  wherein the convolution means comprises a multiplier.