High Accuracy Channel Estimation With TxID Sequence in ATSC 3.0 SFN

Inter-tower communications networks (ITCN) and wireless in-band distribution links (IDL) reuse the same broadcast spectrum for establishing communications links between transmitter towers and for wireless backhaul by multiplexing the ITCN/IDL signals with the broadcast signal into a frame for transmission. In single-frequency networks (SFN) environment, where all the transmitter towers broadcast the same preamble and in-band pilots for improving TV coverage and received signal strength, receiving the desired ITCN/IDL signal from a specific transmitter is challenging with the conventional channel estimation techniques. In the Advanced Television Standard Committee (ATSC) 3.0, one unique transmitter identification (TxID) sequence, a spread sequence overlaid with the preamble signal, is assigned for each transmitter for the purpose of SFN planning and synchronization. By using the TxID sequence, the channel estimation of a specific transmitter becomes feasible. However, the accuracy of existing TxID-based channel estimation is limited due to interferences from the preamble signal and the co-channel TxIDs, as well as the non-orthogonality of the TxID sequence. Several high-accuracy channel estimation schemes based on the TxID sequence are proposed in this paper, which enable IDL and ITCN with very high data rate transmission, e.g., 1024 QAM modulation.