| 摘要 |
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.
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