Patent ID: 7418050

Claim:
In a MIMO communication system having a multiplicity M where M is at least three, the multiplicity of a communication system being the number of overlapping data streams transmitted into a channel of the communication system, a process for transmitting data using fewer than M antennas, the process comprising: encoding a data sequence to be transmitted; splitting the encoded data into a plurality of data streams corresponding to the multiplicity M; independently modulating each of the M data streams; combining, in digital form, at least two of the M modulated data streams using a combiner within the transmitter that emulates combining of the at least two modulated data streams in the channel of the MIMO communication system, thereby producing a first output signal, wherein the act of combining includes combining fewer than all of the modulated data streams; transmitting a MIMO signal, including converting the first output signal to a first radio frequency (RF) signal and transmitting the first RF signal using a single antenna, wherein the act of transmitting further includes in parallel with transmitting the first RF signal, transmitting one of the uncombined modulated data streams as a second RF signal using a second antenna; and transmitting, in the M data streams, training data sufficient to enable the receiver to compute a channel estimate corresponding to each of the M data streams.