Improvements are provided in an OFDM network that uses superposition
coding. A broadcast signal and e.g. a unicast signal are each subjected
to OFDM modulation including processing by an IDFT, combined, and
transmitted using non-orthogonal transmission resources. In one approach,
the respective signals are combined after instead of before the IDFT
processing. In specific examples, a respective cyclic prefix is appended
to each signal after the IDFT processing but before the respective
signals are combined. In another approach, a broadcast pilot signal and
e.g. a unicast pilot signal are transmitted concurrently with the
broadcast and unicast information signals. The pilot signals are
transmitted using the same time and subcarrier resources, but are made
more distinguishable by combining each with a respective scrambling or
spreading code. In specific examples, embodiments, the unicast pilot
signal is used for estimating the data rate for transmission of further
unicast information signals.