Dirty-paper coding techniques for compound MISO broadcast channels: ca DoF analysis

This work investigates optimal Degrees of Freedom (DoF) achieving schemes for the MISO Compound Broadcast Channels (BC) where a source is equipped with M antennas, and communicates with 2 single antennas receivers. We develop a modified Dirty Paper Coding scheme that yields the optimal DoF for some Compound MISO BCs in the complex field. This coding scheme offers a “non-linear” alternative to interference alignment at the receivers which yields higher rates in the finite ranges of power. For asymptotic power regimes, it allows for fractional DoF of 1/2, while being of simple formulation and straightforward application to secondary transmissions in Compound Cognitive networks.