Patent ID: 8542765

Claim:
A method of transmitting a base stream of data and an enhancement stream of data in a wireless communication system, comprising: coding and modulating the base stream to obtain a first data symbol stream, wherein the base stream is designated to be received by a plurality of receiving entities; coding and modulating the enhancement stream to obtain a second data symbol stream, wherein the enhancement stream is designated to be received by at least one receiving entity, and wherein the coding and modulating for the base and enhancement streams are not dependent on channel realizations of receiving entities for the base and enhancement streams; processing the first data symbol stream in accordance with a first spatial processing scheme to obtain a first plurality of symbol substreams; processing the second data symbol stream in accordance with a second spatial processing scheme to obtain a second plurality of symbol substreams, wherein the processing for the first and second data symbol streams is not dependent on the channel realizations of the receiving entities for the base and enhancement streams; and combining the first plurality of symbol substreams with the second plurality of symbol substreams to obtain a plurality of transmit symbol streams for transmission from a plurality of transmit antennas, wherein the combining utilizes a time division multiplexing scheme or a superposition scheme, comprising: scaling the first plurality of symbol substreams that are hierarchically coded with a first scaling factor to obtain a first plurality of scaled symbol substreams, scaling the second plurality of symbol substreams that are hierarchically coded with a second scaling factor to obtain a second plurality of scaled symbol substreams, and performing multiplexing or summing the first plurality of scaled symbol substreams and the second plurality of scaled symbol substreams to obtain the plurality of transmit symbol streams, wherein multiplexing is performed when the time division multiplexing is utilized and summing is performed when the superposition scheme is used.