Investigations on Synchronization Channel Sequences in OFDM Based Evolved UTRA Downlink

This paper presents the optimum primary- synchronization channel (P-SCH) and secondary-SCH (S-SCH) sequences for the SCH based on criteria to achieve fast initial and neighboring cell search time performance in the Evolved UTRA (E-UTRA) downlink. Simulation results show that the P-SCH sequence has a slight influence on the achievable cell search time, and that the application of multiple sequences, i.e., three P-SCH sequences, is beneficial in achieving fast cell search time performance particularly for the neighboring cell search. The results also show that the Walsh-Hadamard sequence or cyclic-shifted orthogonal sequence is suitable for the S-SCH sequence to indicate the cell ID group. Furthermore, it is shown that the combination of a permutation of the orthogonal S-SCH and P-SCH-specific scrambling sequences is advantageous in suppressing the cross-correlation between S-SCHs that collide and in achieving a fast cell search time particularly for the neighboring cell search in inter-node B synchronous operation.