Patent attributes
Multiple-In Multiple-Out (MIMO) techniques are used to increase spectral efficiency of a cellular single frequency network. In some embodiments with single transmit antenna per cell, multiple data streams are transmitted from multiple cells, one data stream per set of transmit antennae. The mapping of streams to antenna sets is permuted in time. In this way, user equipment devices (UEs) at cell edges benefit from MIMO, and UEs near cell centers benefit from high carrier-to-interference (C/I) ratio of the signal. In some embodiments, each stream is concurrently transmitted on base layer of a hierarchically modulated signal from one set, and on enhancement layer of a hierarchically modulated signal from another set. The mapping of sets to streams is permuted in time. The UEs at cell edges benefit from MIMO, and the UEs near cell centers benefit from the high C/I to decode both streams from the base and enhancement layers.
