Method for identifying a code group representative of a number of base stations
View Patent ↗A method and apparatus for identifying a code group representative of a predetermined number of base stations is disclosed. A chip offset within a frame is input into a first correlator. A plurality of samples of chips at which a primary synchronization code (PSC) has been detected are input into the first correlator. Output of the first correlator is multiplied by the complex conjugate of the PSC to obtain a magnitude for the signals being transmitted at the chips inputted into the first correlator. The magnitude is summed over four frames. The summed signals view of a predetermined set of decision variables is evaluated. A case number, a code group, a timeslot location, and a system frame number are determined based on the evaluation and noise estimation.
1. A method for identifying a code group representative of a predetermined number of base stations, comprising:
inputting a chip offset within a frame into a first correlator;
inputting a plurality of samples of chips at which a primary synchronization code (PSC) has been detected into the first correlator;
inputting a peak PSC into a second correlator and taking the complex conjugate of the peak PSC to produce a conjugate of the peak PSC;
multiplying the output of the first correlator by the conjugate of the peak PSC to obtain a magnitude for the signals being transmitted at the chips inputted into the first correlator;
summing the magnitude over four frames;
evaluating the summed signals view of a predetermined set of decision variables; and
determining a case number, a code group, a timeslot location, and system frame number based on said evaluation and a noise estimation.
2. The method of claim 1 wherein the output of the first correlator is multiplied by the complex conjugate of an estimate of the phase of a previously detected primary synchronization code.
3. A wireless transmit/receive unit (WTRU) configured to identify a code group representative of a predetermined number of base stations, comprising:
circuitry configured to input a chip offset within a frame into a first correlator;
circuitry configured to input a plurality of samples of chips at which a primary synchronization code (PSC) has been detected into the first correlator;
circuitry configured to input a peak PSC into a second correlator and taking the complex conjugate of the peak PSC to produce a conjugate of the peak PSC;
circuitry configured to multiply the output of the first correlator by the conjugate of the peak PSC to obtain a magnitude for the signals being transmitted at the chips inputted into the first correlator;
circuitry configured to sum the magnitude over four frames;
circuitry configured to evaluate the summed signals view of a predetermined set of decision variables; and
circuitry configured to determine a case number, a code group, a timeslot location, and system frame number based on said evaluation and a noise estimation.
4. The WTRU of claim 3 further comprising:
circuitry configured to multiply the output of the first correlator by the complex conjugate of an estimate of the phase of a previously detected primary synchronization code.