On the use of TCH sequences for synchronization and channel estimation in MIMO systems

TCH (Tomlinson, Cercas and Hughes) sequences have been studied for code-spreading and channel coding, but their true purpose is for synchronization and channel estimation. This is due to their property of being (virtually) orthogonal to all of their sequences obtained via circular shifts, and the use of the FFT (Fast Fourier Transform) for decoding. This property is extremely useful for time-offset synchronization (there is a distinct “peak” only when both sequences are aligned), and for dispersive channel-estimation (since the multipath-taps are now orthogonal to each other). This work will focus essential on different TCH-based sequences for performing synchronization, channel and noise estimation for OFDM (Orthogonal Frequency Domain Modulation)/SC-FDE (Single-Carrier Frequency Domain Equalization) systems. Results for MIMO (Multiple Input, Multiple Output) can be easily extrapolated from the simulation results.