| 摘要 |
In a wireless digital broadcasting system a data stream 4a is mapped onto a super-frame comprising frames, each frame comprising a time-multiplexed preamble section 2 carrying signalling information and a data section carrying the data stream. The data section is segmented into frequency zones 3a, 3b, 3c, and at least part of the data stream is mapped to a first frequency zone. The preamble section includes signalling information relating to the position and bandwidth of at least the first frequency zone to assist in the reception of the data stream. The frequency bandwidth of the preamble section is greater than the frequency bandwidth of the first frequency zone and so the receiver may use a reduced sampling rate to receive the data stream after initially receiving the preamble in the wider bandwidth, thereby saving power. The wider bandwidth used for the preamble avoids the need to duplicate information in the preamble between frequency zones. |
