Design and Implementation of DTV Receiver

The principles of channel synchronization and channel estimation as well as equalization in the inner receiver for both single- and multicarrier systems are introduced in this chapter, and their applications for the DTMB system is then discussed with some examples. The algorithms for the frequency tracking stage are described and share the requirement of correct timing, which requires that the timing recovery module operate properly within a certain frequency offset range. Unlike the C-OFDM, the time-domain PN sequence instead of the frequency-domain pilot signal is utilized in the TDS-OFDM system, and the receiver can use the PN sequence for channel estimation by acquiring the time-domain impulse response of the channel first and then getting the frequency-domain response through DFT, which is described in detail in the chapter. The channel estimation and equalization methods discussed here are based on the correlation algorithm for the time-domain synchronous PN sequence.