TRANSMITTER AND METHOD OF TRANSMITTING AND RECEIVER AND METHOD OF RECEIVING

摘要

A transmitter transmits data using Orthogonal Frequency Division, OFDM, symbols. The transmitter comprising a forward error correction encoder configured to encode the data to form forward error correction encoded frames of encoded data cells, a service frame builder configured to form a service frame for transmission comprising a plurality of forward error correction encoded frames, a convolutional interleaver comprising a plurality of delay portions and configured to convolutionally interleave the data cells of the service frames, a modulation symbol mapper configured to map the interleaved and encoded data cells of the service frames onto modulation cells, and a modulator configured to modulate the sub-carriers of one or more OFDM symbols with the modulation cells. A controller is configured to form signalling data to be transmitted to include an indication of an identified first cell of a first of the forward error correction frame of a new service frame which can be decoded from cells received from the new service frame or the new service frame and one or more service frames following after the new service frame. By detecting the first cell of a first of the error correction encoded frames of a new service frame which does not have any data cells in one or more previous service frames as a result of the convolutional interleaving then a receiver, which has acquired the new service frame but none of the one or more previous service frames can decode this first forward error correction encoded frame of the new service frame and ignore the other forward error correction encoded frames earlier in the service frame. Therefore for example a receiver may power on or channels during a previous service frame and be directed to only decode a forward error correction encoded frame that it can decode.

主权项

1. A transmitter for transmitting data, the transmitter comprising
a forward error correction encoder configured to encode the data to form forward error correction encoded frames of encoded data cells, a service frame builder configured to form a service frame for transmission comprising a plurality of the forward error correction encoded frames, a convolutional interleaver comprising a plurality of delay portions and configured to convolutionally interleave the encoded data cells of the plurality of the forward error correction encoded frames of the service frames, a modulation symbol mapper configured to map the interleaved and encoded data cells of the service frames onto modulation cells, and a modulator configured to modulate one or more carriers with the modulation cells for transmission, and a controller configured to form signalling data to be transmitted with the service frames to include an indication of an identified first of the encoded data cells of a first of the plurality of forward error correction encoded frames of a service frame which can be decoded from encoded data cells received from the service frame or the service frame and one or more other service frames following after the service frame.