Abstract
With a view to improving the capacity of the differential
OFDM modulation scheme, specified in the narrowband
power line communications (PLC) standards, in combating PLC
channel associated noise, we hereby propose a permutation coded
modulation scheme, which employs the hybridization of two
kinds of DPSK (differential phase shift keying) modulations in
an adaptive manner. The algorithm for deducing the encoded
information from the hybridized modulations is described as well.
This scheme is simulated and its performance is compared with a
recently reported differential quinary PSK-OFDM system in the
literature, whose behaviour has been shown to be better than
the conventional permutation coded D8PSK-OFDM scheme at
lower signal power to noise spectral density. Due to the simplicity
in its encoding and decoding algorithms, this scheme is a good
candidate for a number of low speed telemetry signaling in smart
grids.