Timing phase recovery method and apparatus

A method for timing phase recovery comprising the steps of:

• a. determining an open-eye position using a framed signal burst;
• b. determining a starting position for the framed signal burst;
• c. determining a time offset using the starting position of the framed signal burst;
• d. based on the determined staring position of the framed signal burst, adjusting the starting position of the framed signal burst;
• e. interpolating open-eye samples using an estimated sampling phase and the adjusted starting position of the framed signal burst;
• f. denoising the open-eye samples by normalizing the open-eye samples to minimize the amplitude error;
• g. estimating a channel response using the denoised open-eye samples and the framed signal burst with the adjusted starting position;
• h. correlating the estimated channel response with an ideal channel response to determine a peak position of the correlation, the peak position of the correlation corresponding to an initial time phase estimate;
• and
• i. adding the initial timing phase estimate and the time offset to determine the recovered timing phase.

A method for estimating a time of arrival comprising the steps of:

• a. matched filtering an input signal to produce a matched filtered signal;
• b. buffering the matched filtered signal and adding global positioning system time stamps to produce a buffered signal;
• c. compensating for the carrier frequency offset in the buffered signal to produce a received signal;
• d. determining a start position of a signal burst and framing the signal burst using a framer;
• e. determining an inter-symbol delay from the start position of the signal burst;
• f. determining an open-eye position using the framed signal burst;
• g. determining a starting position for the framed signal burst;
• h. determining a time offset from the starting position of the framed signal burst;
• i. based on the determined starting position of the framed signal burst, adjusting the starting position of the framed signal burst;
• j. interpolating open-eye samples using an estimated sampling phase and the determined starting position of the framed signal burst;
• k. denoising the open-eye samples by normalizing the open-eye samples to minimize the amplitude error;
• l. estimating a channel response using the denoised open-eye samples and the framed signal burst with the adjusted starting position;
• m. correlating the estimated channel response with an ideal channel response to determine a peak position of the correlation, the peak position of the correlation corresponding to an initial timing phase estimate;
• and
• n. adding the initial timing phase estimate and the time offset to determine an intra-symbol delay;
• o. adding the inter-symbol delay and the intra-symbol delay to determine the time of arrival.

A system for timing phase recovery comprising:

• a. means for estimating an open-eye sequence of a received signal;
• b. a channel estimator for estimating a channel response using the open-eye sequence and an adjusted signal;
• and
• c. a correlator for correlating the estimated channel response with an ideal channel response to determine a peak correlation location, the peak correlation location corresponding to the recovered timing phase.