Apparatus and method for transmitting fast feedback information in a wireless communication system
An apparatus is provided for transmitting uplink fast feedback information in a wireless communication system. In the apparatus, a channel encoder generates uplink fast feedback information to transmit, and outputs 3-bit codewords being set according to the fast feedback information. A noncoherent modulator modulates transmission symbols corresponding to the codewords using a noncoherent modulation scheme, and allocates the modulated transmission symbols to each of subcarrier bundles. An inverse fast Fourier transform (IFFT) unit IFFT-processes a transmission signal comprised of the subcarrier bundles before transmission.
1. An apparatus for transmitting uplink fast feedback information in a wireless communication system, the apparatus comprising:
a channel encoder for inputting uplink fast feedback information to transmit, and outputting 3-bit codewords being set according to the fast feedback information;
a noncoherent modulator for modulating transmission symbols corresponding to the codewords using a noncoherent modulation scheme; and
an inverse fast Fourier transform (IFFT) unit for generating a transmission signal comprised of subcarrier bundles by IFFT-processing the modulated transmission symbols before transmission,
wherein the 3-bit codewords are represented as 3-bit payloads as follows:
Fast Feedback Vector Index per Tile
Even = {tile (0), tile (2), tile (4)},
3 bit payload
Odd = {tile (1), tile (3), tile (5)}
0b000
0, 0, 0
0b001
1, 1, 1
0b010
2, 2, 2
0b011
3, 3, 3
0b100
4, 4, 4
0b101
5, 5, 5
0b110
6, 6, 6
0b111
7, 7, 7
wherein the fast feedback vector index is represented as a vector index as follows:
Subcarrier modulation per codeword
VECTOR INDEX
subcarrier 0, subcarrier 1, . . . , subcarrier 7
0
P0, P1, P2, P3, P0, P1, P2, P3
1
P0, P3, P2, P1, P0, P3, P2, P1
2
P0, P0, P1, P1, P2, P2, P3, P3
3
P0, P0, P3, P3, P2, P2, P1, P1
4
P0, P0, P0, P0, P0, P0, P0, P0
5
P0, P2, P0, P2, P0, P2, P0, P2
6
P0, P2, P0, P2, P2, P0, P2, P0
7
P0, P2, P2, P0, P2, P0, P0, P2
and wherein orthogonal vectors P0, P1, P2 and P3, each of which indicates a Quadrature Phase Shift Keying (QPSK) modulation symbol, can be expressed by:
P
0
=
exp
(
j
·
π
4
)
P
1
=
exp
(
j
·
3
π
4
)
P
2
=
exp
(
-
j
·
3
π
4
)
P
3
=
exp
(
-
j
·
π
4
)
.
2. The apparatus of claim 1 , wherein the channel encoder inputs the uplink fast feedback information, and outputs 8 codewords.
3. The apparatus of claim 1 , wherein the transmission signal is transmitted through a fast feedback channel, including at least one subchannel group, each including a predetermined number of subchannels.
4. The apparatus of claim 1 , wherein the codewords are set in an order where a minimum Hamming distance between the codewords defined in a system setup process becomes maximized.
5. An apparatus for receiving uplink fast feedback information in a wireless communication system, the apparatus comprising:
a reception device for receiving a signal transmitted from a transmission apparatus through an uplink fast feedback channel, extracting 3-bit codewords from the received signal, and using fast feedback information acquired by decoding the extracted codewords in transmitting information at a next time,
wherein the 3-bit codewords are represented as 3-bit payload as follows:
Fast Feedback Vector Index per Tile
Even = {tile (0), tile (2), tile (4)},
3 bit payload
Odd = {tile (1), tile (3), tile (5)}
0b000
0, 0, 0
0b001
1, 1, 1
0b010
2, 2, 2
0b011
3, 3, 3
0b100
4, 4, 4
0b101
5, 5, 5
0b110
6, 6, 6
0b111
7, 7, 7
wherein the fast feedback vector index is represented as a vector index as follows:
Subcarrier modulation per codeword
VECTOR INDEX
subcarrier 0, subcarrier 1, . . . , subcarrier 7
0
P0, P1, P2, P3, P0, P1, P2, P3
1
P0, P3, P2, P1, P0, P3, P2, P1
2
P0, P0, P1, P1, P2, P2, P3, P3
3
P0, P0, P3, P3, P2, P2, P1, P1
4
P0, P0, P0, P0, P0, P0, P0, P0
5
P0, P2, P0, P2, P0, P2, P0, P2
6
P0, P2, P0, P2, P2, P0, P2, P0
7
P0, P2, P2, P0, P2, P0, P0, P2
and wherein orthogonal vectors P0, P1, P2 and P3, each of which indicates a Quadrature Phase Shift Keying (QPSK) modulation symbol, can be expressed by:
P
0
=
exp
(
j
·
π
4
)
P
1
=
exp
(
j
·
3
π
4
)
P
2
=
exp
(
-
j
·
3
π
4
)
P
3
=
exp
(
-
j
·
π
4
)
.
6. A method for transmitting uplink fast feedback information in a wireless communication system, the method comprising the steps of:
inputting uplink fast feedback information to transmit, and outputting 3-bit codewords being set according to the fast feedback information;
modulating transmission symbols corresponding to the codewords using a noncoherent modulation scheme; and
generating a transmission signal comprised of subcarrier bundles by performing an inverse fast Fourier transform (IFFT) process on the modulated transmission symbols,
wherein the 3-bit codewords are represented as 3-bit payloads as follows:
Fast Feedback Vector Index per Tile
Even = {tile (0), tile (2), tile (4)},
3-bit payload
Odd = {tile (1), tile (3), tile (5)}
0b000
0, 0, 0
0b001
1, 1, 1
0b010
2, 2, 2
0b011
3, 3, 3
0b100
4, 4, 4
0b101
5, 5, 5
0b110
6, 6, 6
0b111
7, 7, 7
wherein the fast feedback vector index is represented as a vector index as follows:
Subcarrier modulation per codeword
VECTOR INDEX
subcarrier 0, subcarrier 1, . . . , subcarrier 7
0
P0, P1, P2, P3, P0, P1, P2, P3
1
P0, P3, P2, P1, P0, P3, P2, P1
2
P0, P0, P1, P1, P2, P2, P3, P3
3
P0, P0, P3, P3, P2, P2, P1, P1
4
P0, P0, P0, P0, P0, P0, P0, P0
5
P0, P2, P0, P2, P0, P2, P0, P2
6
P0, P2, P0, P2, P2, P0, P2, P0
7
P0, P2, P2, P0, P2, P0, P0, P2
and wherein orthogonal vectors P0, P1, P2 and P3, each of which indicates a Quadrature Phase Shift Keying (QPSK) modulation symbol, can be expressed by:
P
0
=
exp
(
j
·
π
4
)
P
1
=
exp
(
j
·
3
π
4
)
P
2
=
exp
(
-
j
·
3
π
4
)
P
3
=
exp
(
-
j
·
π
4
)
.
7. The method of claim 6 , further comprising inputting the uplink fast feedback information, and outputting 8 codewords.
8. The method of claim 6 , wherein the transmission signal is transmitted through a fast feedback channel, including at least one subchannel group, each including a predetermined number of subchannels.
9. The method of claim 6 , wherein the codewords are set in an order where a minimum Hamming distance between the codewords defined in a system setup process becomes maximized.
10. A method for receiving uplink fast feedback information in a wireless communication system, the method comprising the steps of:
receiving a signal transmitted from a transmission apparatus through an uplink fast feedback channel;
extracting 3-bit codewords from the received signal; and
controlling information transmission at a next time using fast feedback information acquired by decoding the extracted codewords,
wherein the 3-bit codewords are represented as 3-bit payloads as follows:
Fast Feedback Vector Index per Tile
Even = {tile (0), tile (2), tile (4)},
3-bit payload
Odd = {tile (1), tile (3), tile (5)}
0b000
0, 0, 0
0b001
1, 1, 1
0b010
2, 2, 2
0b011
3, 3, 3
0b100
4, 4, 4
0b101
5, 5, 5
0b110
6, 6, 6
0b111
7, 7, 7
wherein the fast feedback vector index is represented as a vector index as follows:
Subcarrier modulation per codeword
VECTOR INDEX
subcarrier 0, subcarrier 1, . . . , subcarrier 7
0
P0, P1, P2, P3, P0, P1, P2, P3
1
P0, P3, P2, P1, P0, P3, P2, P1
2
P0, P0, P1, P1, P2, P2, P3, P3
3
P0, P0, P3, P3, P2, P2, P1, P1
4
P0, P0, P0, P0, P0, P0, P0, P0
5
P0, P2, P0, P2, P0, P2, P0, P2
6
P0, P2, P0, P2, P2, P0, P2, P0
7
P0, P2, P2, P0, P2, P0, P0, P2
and wherein orthogonal vectors P0, P1, P2 and P3, each of which indicates a Quadrature Phase Shift Keying (QPSK) modulation symbol, can be expressed by:
P
0
=
exp
(
j
·
π
4
)
P
1
=
exp
(
j
·
3
π
4
)
P
2
=
exp
(
-
j
·
3
π
4
)
P
3
=
exp
(
-
j
·
π
4
)
.
11. The apparatus of claim 1 , wherein the apparatus receives an indication field, which indicates a fast feedback information transmission scheme, defined as follows:
Indication Field
Length (bits)
Contents
CQICH type
2
00 = 6 bit CQI,
01 = DIUC-CQI
10 = 3 bit CQI (even)
11 = 3 bit CQI (odd).
12. The method of claim 6 , further comprising receiving an indication field, which indicates a fast feedback information transmission scheme, defined as follows:
Indication Field
Length (bits)
Contents
CQICH type
2
00 = 6 bit CQI,
01 = DIUC-CQI
10 = 3 bit CQI (even)
11 = 3 bit CQI (odd).