Synchronization strategy and architecture for spread-spectrum receivers

A synchronization apparatus (400) for a spread-spectrum receiver, the apparatus comprising:

• a code-matched filter (410);
• a running average unit (413) in signal communication with the code-matched filter;
• a peak detector (422) in signal communication with the running average unit;
• and
• a synchronizer (424) in signal communication with the peak detector for providing an index of a peak.

An apparatus for synchronizing the reception of a spread-spectrum signal, the apparatus comprising:

• receiver means for receiving a spread-spectrum signal having a period comprising a plurality of indexable samples;
• array means for maintaining a mean array comprising a running mean value for each indexable sample over a variable number of periods;
• detector means for detecting a peak value of the maintained mean array;
• averaging means for calculating an average value of the maintained mean array;
• processor means for computing a peak-to-average ratio in accordance with the detected peak value and the calculated average value;
• logic means for comparing the peak-to-average ratio against a time- varying threshold;
• and
• synchronizer means for synchronizing the received signal when the peak-to-average ratio exceeds the current value of the time-varying threshold.

A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for synchronizing the reception of a spread-spectrum signal, the method steps comprising:

• receiving a spread-spectrum signal having a period comprising a plurality of indexable samples;
• maintaining a mean array comprising a running mean value for each indexable sample over a variable number of periods;
• detecting a peak value of the maintained mean array;
• calculating an average value of the maintained mean array;
• computing a peak-to-average ratio in accordance with the detected peak value and the calculated average value;
• comparing the peak-to-average ratio against a time-varying threshold;
• and
• synchronizing the received signal when the peak-to-average ratio exceeds the current value of the time-varying threshold.