A CLUSTER FRAME SYNCHRONIZATION SCHEME FOR A SATELLITE DIGITAL AUDIO RADIO SYSTEM

摘要

A satellite digital audio radio system (SDARS) transmitter provides a broadcast transmission signal including a time division multiplex (TDM) mode of transmission and a coded orthogonal frequency multiplex (OFDM) mode of transmission. The SDAR S transmitter provides a transmission signal that supports four transport mechanisms or traffic channels: (1) multiple audio and data program channels (program channels), (2) a cluster control information channel (CC), (3) a global control information channel (GC), and (4) a synchronization channel (CS). In particular, the SDARS transmitter processes 100 program channels into 5 clusters, each cluster comprising GC and CS information, along with a program cluster comprising 20 program channels and CC information. The SDARS transmitter further partitions each cluster into 255 cluster segments and interleaves the cluster segments from each cluster for transmission. The SDA RS uses one identical maximal length PN (pseudo-random number) sequence as a cluster synchronization word for the five clusters. The relative phases of five cluster correlation results is used by a receiver to uniquely identify each individual cluster.< /SDOAB>