Use of periodic pilot tones for identifying base stations of FH-OFDMA systems

A base station (BS) identification scheme for frequency-hopping (FH) orthogonal frequency division multiple access (OFDMA) is proposed. This scheme is based on the use of periodically inserted pilot tones carrying binary information. The identification process consists of two steps. First, locations of pilot tones are detected and second, the binary sequences associated with the pilots are identified. Modified maximum likelihood (ML) rules for the two steps are derived. Computer simulation results demonstrate that the proposed scheme can outperform the existing method that utilizes the slope of a pilot tone hopping sequences, yet it is considerably simpler to implement.