| 摘要 |
PURPOSE: A method and apparatus for searching cells at high speed are provided which uses distributed sample acquisition based on differentially-coherent phase shift keying to simultaneously transmit b status samples for SRG generating PN sequence with a long period and employs a data constellation pre-rotation technique to provide certainty to channel estimation. CONSTITUTION: An apparatus for searching cells and estimating channels using distributed sample acquisition based on differentially-coherent phase shift keying includes a DSA diffusing part, a sample inverse-diffusing part(30), a DSA inverse-diffusing part(40), and a channel estimator. The DSA diffusing part samples b status values of a sequence generator previously and diffuses and scrambles user data whose constellation was pre-rotated to a scrambling sequence. The sample diffusing part modulates the status samples output from the DSA diffusing part into a DPSK symbol and diffuses the keyed symbol to an igniter sequence. The sample inverse-diffusing part acquires a corresponding igniter sequence from the status signal output from the sample diffusing part, inverse-diffuses the status signal input to the acquired igniter sequence and then demodulates the inverse-diffused status signal. The DSA inverse-diffusing part synchronizes sequence generators of a transmitter and receiver with one another, inverse-diffuses and descrambles the diffused user data into a descrambling sequence generated using a main sequence corresponding to the synchronized timing. The channel estimator estimates a channel gain and carrier phase.
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