| 摘要 |
A frame 2 is divided into multiple physical layer (PHY) zones 4a-c. The characteristic configuration in each zone differs from the others, varying the reliability/robustness of the transmission in each zone. Characteristics which may be varied are number of sub-carriers, pilot symbol patterns, MIMO scheme, guard period duration. Signalling 6a-b indicating the locations of the zones, their characteristics and the locations of data stream are typically included in the most robust zone. The zones may be terminated with a pilot pattern 10a-c. The invention may be used with DVB-T2 wireless systems using OFDM modulation. In particular the zones may accommodate different physical layer pipes (PLP) with differing quality of service (QoS) requirements. The invention allows multiple differing quality levels to be accommodated within a single frame. |
