Patent ID: 8107578
Filing Date: 2012-01-31
Classification: H04L

Abstract:
1. A method for identifying receipt of a sync word in a stream of signal data, the sync word comprising an ordered string of predetermined bits having a particular length, the method comprising: receiving a signal value representing an incoming bit in the stream of signal data via a first shift register; inserting the signal value into a first shift register having the same length as the sync word; calculating a bit value from the signal value; storing the bit value into a second shift register having the same length as the sync word; counting the number of matches between the bit values in the second shift register and the corresponding bits in the sync word; computing an energy of the signal data by summing the magnitude of the signal values in the first shift register; computing a correlation of the signal data and the sync word by summing the product of each signal value in the first shift register and the corresponding bit in the sync word; producing a normalized correlation by dividing the correlation by the energy; and outputting a signal indicating the presence of a sync word when both of the following conditions are true: