Simplified timing correction for data despreading of serial offset quadrature pulse-shaped spread signals

A system for correcting timing in a quadrature pulse-shaped spread signal receiver, the system comprising:

• a demodulator front end of the receiver, for receiving a modulated signal and outputting digitized inphase (I) and quadrature (Q) signals;
• a phase rotator, coupled to the demodulator, for receiving the digitized I and Q signals and outputting serial I and Q signals;
• a decimator, coupled to the phase rotator, for receiving the serial I and Q signals and outputting decimated even sampled I and Q signals;
• a SYNC detection module, coupled to the decimator, for receiving the decimated even sampled I and Q signals and outputting a plurality of rake tap locations and rake tap timing corrections for the respective rake tap locations;
• and
• a rake tap processing section, coupled to the SYNC detection module, for receiving the serial I and Q signals and the rake tap timing corrections and outputting I and Q symbols for subsequent data processing.

In a receiver, a method of timing a correction for demodulation of a quadrature pulse shaped signal, the method comprising the steps of:

• (a) obtaining, by the receiver, serial I and Q signals from the quadrature pulse shaped signal;
• (b) decimating, by the receiver, the serial I and Q signals to obtain even and odd I samples and even and odd Q samples;
• (c) selecting, by the receiver, the even or the odd samples for each of a plurality of rake taps based on a correlation profile of the serial I and Q signals;
• (d) obtaining, by the receiver, I and Q symbols for each of the rake taps by despreading either the even or the odd I and Q samples, based on the determination in step (c);
• and
• (e) combining, by the receiver, the I and Q symbols of each of the rake taps to form combined I and Q symbols for subsequent data processing.