| 摘要 |
<p>Methods and apparatus for acquiring and verifying a code used by a base station. Acquisition time is reduced and circuitry simplified by performing Phase I (320) and Phase II (330) acquisitions in series, but in parallel with Phase III acquisition (340) and verification (350), which are done in series. Phase III code acquisition (340) is done by despreading the input signal using each of the possible codes in a code group. An estimation of the frequency offset between the base station and the terminal's local reference is used to correct the phase of the despread signals, which are coherently and non-coherently integrated. The largest accumulated value corresponds to the code used by the base station. The code is verified by despreading (380) the received signal, applying a frequency correction (360), and demodulating. The demodulated output is a series of symbols, and a count of these symbols verifies the acquired code.</p> |
