Synchronizing method and apparatus
AssigneeWavesat Wireless Inc.
InventorsJonathan F. Labs, Greg Beaton, Erick Delage, René Janicek, Jean-François Lacasse, Rainer Ullmann
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Abstract
A method and apparatus is disclosed for performing a synchronization of an incoming series of complex samples of an incoming signal with a known sequence of a plurality of coefficients which represents a pattern within the incoming signal, known to the synchronizer, where the synchronization is performed using a plurality of cross-correlations units.
Claims13
A method of synchronizing an incoming signal, said method comprising:
- extracting a real part and an imaginary part of the incoming signal and a real part and an imaginary part of a sequence of at least one known coefficient;
- extracting a sign for each of the extracted real part and imaginary part of the incoming signal, and the extracted real part and imaginary part of the sequence of at least one coefficient;
- correlating said extracted sign of the extracted real part and imaginary part of the incoming signal and said extracted sign of the real part and imaginary part of the sequence of at least one coefficient to obtain a correlated signal;
- selecting said correlated signal when said correlated signal matches a given criterion;
- and
- synchronizing said incoming signal with said at least one known coefficient using said selected correlated signal wherein said extracting a sign comprises applying a signum function defined as sgn (f)=1 when f≧0 and sgn (f)=−1 when f<0.
A synchronizer for synchronizing a known sequence of coefficients, said sequence of coefficients having a real part and an imaginary part, to an incoming input signal, said incoming input signal having a real part and an imaginary part, the synchronizer comprising:
- a calculator for extracting a sign for each of the real part and imaginary part of the sequence of coefficients, and real part and imaginary part of the incoming input signal;
- a first correlation unit for correlating said sign of said imaginary part of said incoming input signal with said sign of said imaginary part of said sequence of at least one coefficient to provide a first correlated signal;
- a second correlation unit for correlating said sign of said real part of said incoming input signal with said sign of said real part of said sequence of at least one coefficient to provide a second correlated signal;
- a third correlation unit for correlating said sign of said imaginary part of said incoming input signal with said sign of said real part of said sequence of at least one coefficient to provide a third correlated signal;
- a fourth correlation unit for correlating said sign of said real part of said incoming input signal with said sign of said imaginary part of said sequence of at least one coefficient to provide a fourth correlated signal;
- a first adding unit subtracting said first correlated signal and said second correlated signal to “4” to provide a first added signal;
- a second adding unit subtracting said third correlated signal and adding said fourth correlated signal to provide a second added signal;
- and
- a criterion matching unit determining which of said first added signal and said second added signal matches a given criterion.
A synchronizer for determining when an incoming signal, having an arbitrary power value, matches at least one known coefficient, said synchronizer comprising:
- a quantizer determining a quantization bit indicative of said arbitrary power value, the quantizer applying a signum function to said arbitrary power value to obtain the quantization bit;
- a correlator to correlate said quantization bit with said at least one known coefficient to obtain a correlated signal;
- and
- a selector to select said correlated signal when said correlated signal matches a given criterion.
Dependencies are inferred from the claim text.