Transmitter and method of transmitting and receiver and method of receiving

摘要

A transmitter encodes data into forward error correction encoded (FEC) frames of encoded data cells. Plural FEC frames are formed into service frames for transmission. A convolutional interleaver interleaves the data cells of the service frames before modulation onto OFDM sub-carriers. A receiver which powers on and receives a new service frame may fail to decode an FEC frame contained therein because some of the data cells of the FEC frame have already been transmitted in a previous service frame. To save on energy wasted trying to decode the FEC frame the invention proposes either that the transmitter indicates to the receiver a first cell of a first FEC frame in a service frame it is able to decode or the receiver calculates which FEC frame it is able decode without requiring data cells of previous service frames.