FIELD: information technology.
SUBSTANCE: pilot signal can be generated based on a multi-phase sequence and using single-carrier frequency-division multiple access (SC-FDMA). SC-FDMA includes interleaved FDMA (IFDMA), in which data and/or pilot signal are transmitted in sub-bands, and localised FDMA (LFDMA), in which data and/or pilot signal are usually transmitted in adjacent sub-bands among all K sub-bands. A transmitter generates a pilot signal which has a constant envelope in the time domain and a uniform frequency spectrum, based on the multi-phase sequence. To generate an IFDMA pilot symbol, the first sequence of pilot symbols is generated based on the multi-phase sequence, and is repeated many times to obtain a second sequence of pilot symbols. A saw-tooth phase signal is applied to the second sequence of pilot symbols to obtain a third sequence of output symbols. A periodic prefix is added to the third sequence of output symbols to obtain an IFDMA symbol which is transmitted in the time domain through a communication channel. Pilot symbols can be multiplexed with data symbols using TDM and/or CDM. An LFDMA pilot symbol can also be generated using a multi-phase sequence and can be multiplexed using TDM or CDM. A receiver receives channel evaluation based on the received pilot symbols and using a minimum mean square error technique, a least square technique or any other channel evaluation technique.
EFFECT: reduced adverse effect of high ratio of maximum power to average power during multi-carrier modulation.
59 cl, 21 dwg
