Method for transmitting a sequence of symbols for exploiting transmit diversity
An embodiment of a method for transmitting data through at least a channel in a wireless communication system, the method comprising at least the steps of: encoding the data by performing a forward-error-correction encoding, forming a sequence of symbols from the encoded data, forming an M-by-T coding matrix from said sequence of symbols, each column of the coding matrix comprising N different symbols of the sequence of symbols and M−N zeros, N being an integer equal at least to one, T representing the number of consecutive transmission intervals, M representing the total number of transmit antennas, and using the coding matrix for transmitting the sequence of symbols during the T consecutive transmission intervals, by transmitting one different column of the coding matrix at each transmission interval through the M transmit antennas, only N transmit antennas are enabled during a given transmission interval.
1. A method for transmitting data through at least a channel in a wireless communication system, the method comprising:
encoding the data by performing a forward-error-correction encoding,
forming a sequence of independent symbols from the encoded data,
forming an M-by-T coding matrix from said sequence of independent symbols, said coding matrix comprising only the symbols of said sequence of independent symbols and zeros, each column of the coding matrix comprising N different symbols of the sequence of symbols and M−N zeros, N being an integer equal at least to one, T being an integer equal at least to two and representing the number of consecutive transmission intervals, M being an integer greater than N and representing the total number of transmit antennas, at least two columns of said coding matrix having zeros at different locations, and
using the coding matrix for transmitting the sequence of independent symbols during the T consecutive transmission intervals, by transmitting one different column of the coding matrix at each transmission interval through N transmit antennas over the M transmit antennas.
2. The method according to claim 1 , wherein the coding matrix is defined as:
X
4
=
[
s
1
0
s
2
0
0
s
3
0
s
4
]
,
being the coding matrix, and
s 1 , s 2 , s 3 , s 4 being respectively first, second, third and fourth symbols forming the sequence of symbols.
3. The method according to claim 1 , wherein the coding matrix comprises symbols with swapped in-phase and quadrature components over time and spatial dimensions.
4. The method according to claim 1 wherein the sequence of symbols is transmitted over frequency and spatial dimensions.
5. The method according to claim 2 , wherein the sequence of symbols is transmitted over frequency and spatial dimensions.
6. The method according to claim 3 , wherein the sequence of symbols is transmitted over frequency and spatial dimensions.
7. The method according to claim 1 , wherein the sequence of symbols is transmitted over frequency, time and spatial dimensions.
8. The method according to claim 2 , wherein the sequence of symbols is transmitted over frequency, time and spatial dimensions.
9. The method according to claim 3 , wherein the sequence of symbols is transmitted over frequency, time and spatial dimensions.
10. A method for transmitting data through at least a channel in a wireless communication system, the method comprising:
encoding the data by performing a forward-error-correction encoding,
forming a sequence of independent symbols from the encoded data,
forming an M-by-T coding matrix from said sequence of independent symbols, said coding matrix comprising only the symbols of said sequence of independent symbols and zeros, each column of the coding matrix comprising N different symbols of the sequence of symbols and M−N zeros, N being an integer equal at least to one, T being an integer equal at least to two and representing the number of consecutive transmission intervals, M being an integer greater than N and representing the total number of transmit antennas, at least two columns of said coding matrix having zeros at different locations, and
using the coding matrix for transmitting the sequence of independent symbols during the T consecutive transmission intervals, by transmitting one different column of the coding matrix at each transmission interval through N transmit antennas over the M transmit antennas;
wherein the coding matrix comprises rotated symbols with swapped in-phase and quadrature components over time and spatial dimensions; and
wherein the coding matrix is defined as:
X
3
=
[
s
~
0
0
s
~
1
s
~
2
0
s
~
3
]
,
{tilde over (s)} k being defined as {tilde over (s)} k =Re{s k e jθ }+jIm{s l e jθ }, for k=0 to 3, l=k+2 modulo 4.
11. The method according to claim 10 , wherein the sequence of symbols is transmitted over frequency and spatial dimensions.
12. The method according to claim 10 , wherein the sequence of symbols is transmitted over frequency, time and spatial dimensions.
13. A device for transmitting an input signal through at least a channel in a wireless communication system, the device comprising:
a forward-error correction encoder for encoding the input signal,
a plurality of transmit antennas, and
a mapping module configured to:
encode data by performing a forward-error-correction encoding,
form a sequence of independent symbols from the encoded data,
form an M-by-T coding matrix from said sequence of independent symbols, said coding matrix comprising only the symbols of said sequence of independent symbols and zeros, each column of the coding matrix comprising N different symbols of the sequence of symbols and M−N zeros, N being an integer equal at least to one, T being an integer equal at least to two and representing the number of consecutive transmission intervals, M being an integer greater than N and representing the total number of transmit antennas, at least two columns of said coding matrix having zeros at different locations, and
use the coding matrix for transmitting the sequence of independent symbols during the T consecutive transmission intervals, by transmitting one different column of the coding matrix at each transmission interval through N transmit antennas over the M transmit antennas.
14. The system according to claim 13 , wherein the coding matrix is defined as:
X
4
=
[
s
1
0
s
2
0
0
s
3
0
s
4
]
,
being the coding matrix, and
s 1 , s 2 , s 3 , s 4 being respectively first, second, third and fourth symbols forming the sequence of symbols.
15. The system according to claim 13 , wherein the coding matrix comprises symbols with swapped in-phase and quadrature components over time and spatial dimensions.
16. The system according to claim 13 , wherein the coding matrix is defined as:
X
3
=
[
s
~
0
0
s
~
1
s
~
2
0
s
~
3
]
,
{tilde over (s)} k being defined as {tilde over (s)} k =Re{s k e jθ }+jIm{s l e jθ }, for k=0 to 3, l=k+2 modulo 4.
17. The system according to claim 13 , wherein the sequence of symbols is transmitted over frequency and spatial dimensions.
18. The system according to claim 13 , wherein the sequence of symbols is transmitted over frequency, time and spatial dimensions.