Multiple streams using STBC with higher data rates and diversity gain within a wireless local area network
A method of communicating data to M receiving antennas from N transmitting antennas, where M and N are integers, the method includes the steps of producing N data streams from outbound data, applying the N data streams to a space/time encoder to produce N encoded signals and transmitting the N encoded signals from N transmitting antennas. At least P transmitting antennas transmit space-time block-coded signals and (N-P) transmitting antennas transmit repetition code signals, where P is an integer. The transmission of the N encoded signals is performed such that the M receiving antennas receive at least three Orthogonal Frequency Division Multiplexing (OFDM) symbols per tone.
1 . A method of communicating data to M receiving antennas from N transmitting antennas, where M and N are integers, the method comprising the steps of:
producing N data streams from outbound data;
applying the N data streams to a space/time encoder to produce N encoded signals; and
transmitting the N encoded signals from N transmitting antennas;
wherein at least P transmitting antennas transmit space-time block-coded signals and (N-P) transmitting antennas transmit repetition code signals, where P is an integer.
2 . The method of claim 1 , wherein the step of transmitting the N encoded signals is performed such that the M receiving antennas receive at least three Orthogonal Frequency Division Multiplexing (OFDM) symbols per tone.
3 . The method of claim 1 , wherein P comprises two and the step of transmitting the N encoded signals comprises transmitting two space-time block-coded signals over two transmit antennas.
4 . The method of claim 3 , wherein N comprises three and the step of transmitting the N encoded signals comprises transmitting a repetition code signal over one transmit antenna.
5 . A method according to claim 1 , wherein the step of applying the N data streams to a space/time encoder is performed such that the outbound data is reconstituted by zero-forcing terms equivalent to relationships between signals sent from the N transmitting antennas to the M receiving antennas to cancel interference.
6 . A method according to claim 5 , wherein the relationships comprise:
[
r
1
r
2
]
=
[
H
1
G
1
H
2
G
2
]
[
c
1
c
2
]
+
[
n
1
n
2
]
where
,
c
1
=
[
c
1
(
t
0
)
c
1
(
t
1
)
]
,
c
2
=
[
c
2
(
t
0
)
]
,
r
1
=
[
r
1
(
t
1
)
r
1
*
(
t
2
)
]
,
r
2
=
[
r
2
(
t
1
)
r
2
*
(
t
2
)
]
,
H
i
=
[
h
1
i
h
2
i
h
2
i
*
-
h
1
i
*
]
,
G
i
=
[
g
i
g
i
*
]
,
where r i (t) and c i (t) are the received and transmitted signals, respectively, n i represent noise terms and G i and H i represent relationships between signals sent from the N transmitting antennas to the M receiving antennas.
7 . The method of claim 6 , wherein the cancellation of the interference through zero forcing comprises:
[
[
1
0
0
1
]
[
-
g
1
g
2
-
1
0
0
-
g
1
*
g
2
-
1
*
]
a
b
c
d
]
3
×
4
×
[
r
1
r
2
]
=
[
r
~
1
r
~
2
]
=
[
H
~
0
0
G
~
]
3
×
3
×
[
c
1
c
2
]
+
[
n
~
1
n
~
2
]
where
,
H
~
2
×
2
=
H
1
-
[
-
g
1
g
2
-
1
0
0
-
g
1
*
g
2
-
1
*
]
×
H
2
,
G
~
1
×
1
=
g
1
2
+
g
2
2
,
and a, b, c, d satisfy the following equation,
[
a
b
c
d
]
=
[
h
11
h
21
*
h
12
h
22
*
h
21
-
h
11
*
h
22
-
h
12
*
g
1
g
1
*
0
0
0
0
g
2
g
2
*
]
-
1
×
[
0
0
g
1
2
g
2
2
]
.
8 . The method of claim 1 , wherein P=(⅔)*N and the step of transmitting the N encoded signals comprises transmitting P space-time block-coded signals through P transmit antennas.
9 . A transmitter for communicating data from N transmitting antennas to M receiving antennas, where M and N are integers, comprising:
streaming means for producing N data streams from outbound data;
encoding means for applying the N data streams to a space/time encoder to produce N encoded signals; and
N transmit antenna means for transmitting N encoded signals to M receiving antennas;
wherein the encoding means provides at least P space-time block-coded signals to P transmit antenna means and provides (N-P) repetition code signals to (N-P) transmit antennas, where P is an integer.
10 . The transmitter of claim 9 , wherein the encoding means is configured to provide the N encoded signals such that the M receiving antennas receive at least three Orthogonal Frequency Division Multiplexing (OFDM) symbols per tone.
11 . The transmitter of claim 9 , wherein P comprises two and the transmitting means transmit two space-time block-coded signals over two transmit antennas.
12 . The transmitter of claim 11 , wherein N comprises three and the transmitting means transmit a repetition code signal over one transmit antenna.
13 . A transmitter according to claim 9 , wherein the encoding means is configured to encode the N data streams such that the outbound data is reconstituted by zero-forcing terms equivalent to relationships between signals sent from the N transmitting antennas to the M receiving antennas to cancel interference.
14 . A transmitter according to claim 13 , wherein the relationships comprise:
[
r
1
r
2
]
=
[
H
1
G
1
H
2
G
2
]
[
c
1
c
2
]
+
[
n
1
n
2
]
where
,
c
1
=
[
c
1
(
t
0
)
c
1
(
t
1
)
]
,
c
2
=
[
c
2
(
t
0
)
]
,
r
1
=
[
r
1
(
t
1
)
r
1
*
(
t
2
)
]
,
r
2
=
[
r
2
(
t
1
)
r
2
*
(
t
2
)
]
,
H
i
=
[
h
1
i
h
2
i
h
2
i
*
-
h
1
i
*
]
,
G
i
=
[
g
i
g
i
*
]
,
where r i (t) and c i (t) are the received and transmitted signals, respectively, n i represent noise terms and G i and H i represent relationships between signals sent from the N transmitting antennas to the M receiving antennas.
15 . The transmitter of claim 14 , wherein the cancellation of the interference through zero forcing comprises:
[
[
1
0
0
1
]
[
-
g
1
g
2
-
1
0
0
-
g
1
*
g
2
-
1
*
]
a
b
c
d
]
3
×
4
×
[
r
1
r
2
]
=
[
r
~
1
r
~
2
]
=
[
H
~
0
0
G
~
]
3
×
3
×
[
c
1
c
2
]
+
[
n
~
1
n
~
2
]
where
,
H
~
2
×
2
=
H
1
-
[
-
g
1
g
2
-
1
0
0
-
g
1
*
g
2
-
1
*
]
×
H
2
,
G
~
1
×
1
=
g
1
2
+
g
2
2
,
and a, b, c, d satisfy the following equation,
[
a
b
c
d
]
=
[
h
11
h
21
*
h
12
h
22
*
h
21
-
h
11
*
h
22
-
h
12
*
g
1
g
1
*
0
0
0
0
g
2
g
2
*
]
-
1
×
[
0
0
g
1
2
g
2
2
]
.
16 . The transmitter of claim 9 , wherein P=(⅔)*N and N transmit antenna means transmitting P space-time block-coded signals through P transmit antennas.
17 . A transmitter for communicating data from N transmitting antennas to M receiving antennas, where M and N are integers, comprising:
a demultiplexer, configured to provide N data streams from outbound data;
a space/time encoder, configured to receive the N data streams and supply N encoded signals; and
N transmit antennas, configured to transmit the N encoded signals;
wherein the space/time encoder provides at least P space-time block-coded signals to P transmit antenna means and provides (N-P) repetition code signals to (N-P) transmit antennas, where P is an integer.
18 . The transmitter of claim 17 , wherein the space/time encoder is configured to provide the N encoded signals such that the M receiving antennas receive at least three Orthogonal Frequency Division Multiplexing (OFDM) symbols per tone.
19 . The transmitter of claim 17 , wherein P comprises two and the space/time encoder is configured to provide two space-time block-coded signals to two transmit antennas.
20 . The transmitter of claim 19 , wherein N comprises three and the space/time encoder is configured to provide a repetition code signal to one transmit antenna.
21 . A transmitter according to claim 17 , wherein the space/time encoder is configured to encode the N data streams such that the outbound data is reconstituted by zero-forcing terms equivalent to relationships between signals sent from the N transmitting antennas to the M receiving antennas to cancel interference.
22 . A transmitter according to claim 21 , wherein the relationships comprise:
[
r
1
r
2
]
=
[
H
1
G
1
H
2
G
2
]
[
c
1
c
2
]
+
[
n
1
n
2
]
where
,
c
1
=
[
c
1
(
t
0
)
c
1
(
t
1
)
]
,
c
2
=
[
c
2
(
t
0
)
]
,
r
1
=
[
r
1
(
t
1
)
r
1
*
(
t
2
)
]
,
r
2
=
[
r
2
(
t
1
)
r
2
*
(
t
2
)
]
,
H
i
=
[
h
1
i
h
2
i
h
2
i
*
-
h
1
i
*
]
,
G
i
=
[
g
i
g
i
*
]
,
where r i (t) and c i (t) are the received and transmitted signals, respectively, n i represent noise terms and G i and H i represent relationships between signals sent from the N transmitting antennas to the M receiving antennas.
23 . The transmitter of claim 22 , wherein the cancellation of the interference through zero forcing comprises:
[
[
1
0
0
1
]
[
-
g
1
g
2
-
1
0
0
-
g
1
*
g
2
-
1
*
]
a
b
c
d
]
3
×
4
×
[
r
1
r
2
]
=
[
r
~
1
r
~
2
]
=
[
H
~
0
0
G
~
]
3
×
3
×
[
c
1
c
2
]
+
[
n
~
1
n
~
2
]
where
,
H
~
2
×
2
=
H
1
-
[
-
g
1
g
2
-
1
0
0
-
g
1
*
g
2
-
1
*
]
×
H
2
,
G
~
1
×
1
=
g
1
2
+
g
2
2
,
and a, b, c, d satisfy the following equation,
[
a
b
c
d
]
=
[
h
11
h
21
*
h
12
h
22
*
h
21
-
h
11
*
h
22
-
h
12
*
g
1
g
1
*
0
0
0
0
g
2
g
2
*
]
-
1
×
[
0
0
g
1
2
g
2
2
]
.
24 . The transmitter of claim 17 , wherein P=(⅔)*N and N transmit antennas transmitting P space-time block-coded signals through P transmit antennas.