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The very advancing theory of Space-Time
(ST) codes has attracted many researchers to study their
performance and design criteria. We have proposed and patented the
design of space-time codes for PLC in order to for improve the
reliability of data communication over the channel. Data is to be
encoded by a channel coder and the encoded data is split in to three
phases of 415V power line as transmit antennas. The received signal at
each receive phase “antenna” is a linear superposition of 3 transmitted
signal disturbed by channel noise. Diversity techniques are based on the
notion that errors in reception when the channel attenuation is large
i.e. when the channel is in a deep fade. If we can supply to the
receiver several replicas of the same information signal transmitted
over independently fading corrupted by the noise of the channel, the
probability that all the signal components will fade simultaneously is
reduced considerably. Within the proposed patent suggested to
explore this by assuming each phase of the power line as a transmitting
antenna and in doing so design codes specific for time varying fading
power line channel and finally evaluate performance of these codes over
different rates etc. Figure below shows a typical electricity supply to dwellings with
in the UK.
Constellation
Mapper to transmission matrix three phases
PLC Channel
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