Patent ID: 8976842
Filing Date: 2015-03-10
Classification: H04B

Abstract:
1. A method of detecting PN code synchronization for a direct sequence spread spectrum (DSSS) signal comprising: receiving, by a demodulator, a DSSS data signal comprising a data stream of data frames comprised of I and Q symbols, at least a portion of each data frame comprising a unique word; demodulating, by the demodulator, the data signal into I and Q chip samples; filtering, by a filter, the I and Q chip samples and outputting the filtered I and Q chip samples to a chip stream controller; outputting, by the chip stream controller, a plurality of chip streams to an m×n correlation matrix; correlating the plurality of chip streams with the chipped unique word using m×n correlation cells within the correlation matrix and outputting a correlated data stream; running a plurality of Fast Fourier Transforms (FFTs) on the correlated output data stream and searching for a frequency bin having a maximum frequency bin power of each FFT run using a processor; searching for a maximum frequency bin power among the plurality of FFT runs using a PN synchronization detector; determining, by the PN synchronization detector, whether PN synchronization is present; and determining an offset frequency and identifying a primary chip stream and a secondary chip stream.