Methods of, and apparatus for, synchronizing a receiver with a received signal

A computer readable medium containing computer-executable instructions for causing a data processing apparatus to synchronize a receiver to a received signal, comprising a series of chips arranged in a successive periods, by performing the steps comprising:

• correlating a synchronization word with at least one period-length of the received signal;
• accumulating the correlation results to produce first cumulative correlation results;
• terminating the accumulation of the first cumulative correlation results after processing a first number of said period-lengths when the first cumulative correlation results exceed a threshold;
• examining the first cumulative correlation results to make a first determination of the position of the synchronization word in the received signal;
• displacing the beginnings of the period-lengths to produce a second number of shifted lengths;
• correlating the synchronization word with said first number of shifted lengths to produce second cumulative correlation results;
• and
• examining the second cumulative correlation results to make a second determination of the position of the synchronization word in the received signal.

An apparatus for synchronizing a receiver to a received signal comprising a series of chips arranged in successive periods, the apparatus comprising:

• a correlator for correlating a synchronization word with at least one period-length of the received signal;
• an accumulator for accumulating the correlation results to produce first cumulative correlation results;
• an assessor for examining the first cumulative correlation results make a first determination of the position of the synchronization word in the received signal;
• a controller for terminating the accumulation of the first cumulative correlation results after processing a first number of said period-lengths if the first cumulative correlation results exceed a threshold;
• an assessor for examining the first cumulative correlation results to make a first determination of the position of the synchronization word in the received signal;
• and
• a shifter for displacing the beginnings of the period-lengths to produce a second number of shifted lengths;
• wherein:
• the controller is arranged to correlate the synchronization word with said first number of shifted lengths to produce second cumulative correlation results;
• and
• the assessor is arranged to examine the second cumulative correlation results to make a second determination of the position of the synchronization word in the received signal.