Spectral efficiency of OCDMA/OCDMA with asymmetric power assignment

摘要

The sum capacity of the OCDMA/OCDMA (O/O) signature sequence set is investigated when the users of the two orthogonal sets are allowed to have a different average-input-energy constraint and with perfect synchronization of the users. It is found that the sum capacity is dependent on the load and the respective SNR only, but independent of the choice of the orthogonal sets. For a fixed total power and when the power constraints of the two user sets are allowed to be different, it is shown that the sum capacity of the O/O system can be made arbitrarily close to the sum capacity of the Gaussian multiple access channel.