High data rate closed loop MIMO scheme combining transmit diversity and data multiplexing
View Patent ↗Closed loop multiple-antenna wireless communications system with antenna weights determined by maximizing a composite channel signal-to-interference-plus-noise ratio minimum. Multiplexed symbol streams over subsets of antennas enhance throughout.
1. A wireless transmitter comprising:
A. symbol mapping circuitry having a data symbol output;
B. serial to parallel circuitry having an input coupled with the data symbol output and having plural symbol stream outputs;
C. multiplier circuits, one for each symbol stream output, each multiplier circuit having a symbol input, an antenna weight input, and an antenna output, the symbol input being coupled with a symbol stream output;
D. antenna units, each coupled with the antenna output of one multiplier circuit; and
E. antenna weight circuitry having plural antenna weight outputs, each antenna weight output being coupled with one antenna weight input, the antenna weight circuitry producing weight signals on the antenna weight outputs in accordance with a matrix V, where
V
=
[
R
1
R
2
⋮
R
PbyM
]
and R m is a M by M unitary rotation matrix, in which for M=2:
R
=
[
cos
θ
m
ⅇ
jϕ
m
sin
θ
m
-
ⅇ
jϕ
m
sin
θ
m
cos
θ
m
]
where φ m and θ m can be quantized for low-complexity searching to find V.
2. The wireless transmitter of claim 1 in which the transmitter is included in user equipment.
3. The wireless transmitter of claim 1 in which the transmitter is included in a mobile device.