Signal generation using phase-shift based pre-coding
A phase-shift based pre-coding scheme used in a transmitting side and a receiving side that has less complexity than those of a space-time coding scheme, that can support various spatial multiplexing rates while maintaining the advantages of the phase-shift diversity scheme, that has less channel sensitivity than that of the pre-coding scheme, and that only requires a low capacity codebook is provided.
1. A method of transmitting data sequences via two antennas, the method comprising:
modulating at least one source signal to produce a plurality of modulated symbols;
inputting the plurality of modulated symbols to a pre-coder;
performing, at the pre-coder, a phase-shift-based pre-coding of the plurality of modulated symbols using a first matrix
1
2
(
1
-
ⅇ
j
θ
1
k
ⅇ
j
θ
1
k
1
)
when a multiplexing rate equals 2, and using a second matrix when the multiplexing rate equals 1, the second matrix being a 2×1 matrix and comprising only the first column of the first matrix or the second column of the first matrix,
wherein k denotes a resource index and θ 1 denotes a phase angle; and
transmitting the phase-shift-based pre-coded plurality of modulated symbols via the two antennas.
2. The method of claim 1 , wherein the first matrix is in a form of a codebook.
3. An apparatus for transmitting data sequences via two antennas, the apparatus comprising:
a mapper for modulating at least one source signal to produce a plurality of modulated symbols;
a pre-coder for receiving the plurality of modulated symbols from the mapper and performing a phase-shift-based pre-coding of the plurality of modulated symbols using a first matrix
1
2
(
1
-
ⅇ
j
θ
1
k
ⅇ
j
θ
1
k
1
)
when a multiplexing rate equals 2, and using a second matrix when the multiplexing rate equals 1, the second matrix being a 2×1 matrix and comprising only the first column of the first matrix or the second column of the first matrix,
wherein k denotes a resource index and θ 1 denotes a phase angle; and
a transmitter for transmitting the phase-shift-based pre-coded plurality of modulated symbols via the two antennas.
4. The apparatus of claim 3 , further comprising a memory unit for storing the first matrix in a form of a codebook.