Adaptive Frequency Division Multiplexing wherein Channel Maps are transmitted such that whole copy always falls within Receiver Bandwidth

摘要

An adaptive FDM (Frequency Division Multiplex) system, possibly for DVB-C (Digital Video Broadcasting - Cable) COFDM application, where the frequency bands for TS (transport streams) 330 are of variable width. Superframes comprise a preamble 310, L1 (layer 1) control data 320 including a map detailing the TS centre frequency 360, bandwidth, modulation, etc. and then one or more TS. Receivers have a maximum bandwidth 370 which may be less than the channel 300 bandwidth. The bandwidth of the L1 data is less than half the receiver bandwidth. Thus a copy of the L1 data can be received irrespective of the receivers centre frequency. Using the L1 data the receiver can then align itself to and receive a particular TS.