Dtv Transmitter Identification Using Embedded Pseudo Random Sequences

A transmitter identification system using embedded spread spectrum sequence is proposed. Code generators are developed to study the auto-correlation and cross-correlation properties of the truncated Gold and Kasami sequences. To reduce the computation complexity, the embedded Kasami sequence is time-synchronized with the DTV frame structure. Therefore, the Kasami sequence length has to be truncated to fit into an ATSC DTV signal field. In this paper, the impact of the truncation noise and in-band DTV interference to the transmitter identification process is investigated. It is shown that the auto-correlation and cross-correlation properties are only slightly affected due to the truncation noises. However, the dominant interference to the transmitter identification is the in-band DTV signal. The signal to truncation noise ratio and signal to DTV interference ratio in the correlator output are derived and verified by computer simulation. The inband DTV interference can only by mitigated by increasing the code length or by averaging technique to smooth out the in-band interference.