Low power asynchronous GPS baseband processor

A method for clockless GPS baseband processing, the method comprising:

• a) receiving an input signal for one channel from an RF front and;
• b) providing the input signal to a code numerically controlled oscillator (NCO) and a carrier NCO;
• c) using overflows in the code NCO to mark a predetermined code period, thereby forming an accumulation interval and referencing time to sampling in the input signal;
• d) obtaining, from output of the carrier NCO and the code NCO, early, prompt and late phase and quadrature accumulations;
• e) obtaining code offset and Doppler frequency estimates for the one channel;
• f) tracking deviations in code offset and Doppler frequency for the one channel, using the early, prompt and late phase and quadrature accumulations;
• g) obtaining GPS satellite time and code start time from code offset and Doppler frequency information and the input signal;
• and
• h) repeating steps (a)-(g) until all channels have been processed;
• wherein all steps are performed asynchronously.