| 摘要 |
A method operates a wireless mobile or user station to receive a time slot sent through a radio channel from a transmitter, the time slot being coherently modulated except for a portion that contains a predetermined symbol sequence that is differentially modulated. A next step differentially detects the portion of the received time slot that contains the predetermined symbol sequence. A further step of the method operates to perform a channel estimation for a coherent detector that is used to detect other portions of the time slot. By example, the predetermined symbol sequence is modulated in accordance with one of Differential Quadrature Phase Shift Keying (DQPSK), Differential 8 Phase Shift Keying (D8PSK), pi /4-shifted DQPSK, or 16 level DQPSK. In a preferred embodiment of the invention the portion of the time slot that is differentially modulated is a CDVCC/PILOT field, while the data fields and other fields are modulated using 8PSK. |
