| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an apparatus for generating a pilot having a constant time-domain envelope and a flat frequency spectrum based on a polyphase sequence. <P>SOLUTION: In a transmitter, to generate a pilot IFDMA symbol, a first sequence of pilot symbols is formed based on a polyphase sequence and replicated multiple times to obtain a second sequence of pilot symbols. A phase ramp is applied to the second pilot sequence to obtain a third sequence of output symbols. A cyclic prefix is appended to the third sequence of output symbols to obtain an IFDMA symbol, which is transmitted in the time domain via a communication channel. A pilot LFDMA symbol may also be generated with a polyphase sequence and multiplexed using TDM or CDM. A receiver derives a channel estimate based on received pilot symbols and using minimum mean-square error. <P>COPYRIGHT: (C)2011,JPO&INPIT |
