US 8,477,883 B2Granted

Maximum likelihood decoding method, equipment, and receiver

AssigneeHitachi Kokusai Electric Inc.

InventorsHironari Masui, Takashi Yano, Takehiko Kobayashi

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Abstract

Provided is a maximum likelihood decoding method of separating and estimating multiple transmitted signals transmitted by multiple transmitter antennas from multiple received signals received by multiple receiver antennas, comprising: a first step of generating a channel matrix based on channel impulse responses corresponding to the received signals; a second step of dividing the generated channel matrix into multiple sub-matrices, of identifying parts of the received signals corresponding to the sub-matrices obtained through the division, and of transforming the sub-matrices obtained through the division, by using inverse matrices of the sub-matrices obtained through the division; a third step of applying QR decomposition to the transformed sub-matrices to obtain triangular matrices, and of transforming the received signals of the parts by using the obtained triangular matrices; and a fourth step of determining one combination candidate for the parts of the transmitted signals corresponding to the transformed received signals.

Claims16

Dependent claims

A maximum likelihood decoding method of separating and estimating multiple transmitted signals transmitted by multiple transmitter antennas from multiple received signals received by multiple receiver antennas, comprising:

a first step of generating a channel matrix based on channel impulse responses corresponding to the received signals;
a second step of dividing the generated channel matrix H, into multiple sub-matrices hij, in which the generated channel matrix H is defined as:
H
=
[
h
11
h
12
h
13
h
14
h
21
h
22
h
23
h
24
h
31
h
32
h
33
h
34
h
41
h
42
h
43
h
44
]
and, in which said sub-matrices hij each have a same size and are defined as:
H
11
=
[
h
11
h
12
h
21
h
22
]
⁢
⁢
H
12
=
[
h
13
h
14
h
23
h
24
]
⁢
⁢
H
21
=
[
h
31
h
32
h
41
h
42
]
⁢
⁢
and
⁢
⁢
H
22
=
[
h
33
h
34
h
43
h
44
]
.
in which said sub-matrices are comprised of identifying parts of the received signals corresponding to the sub-matrices obtained through the division, and of transforming the sub-matrices, obtained through the division, by using inverse matrices of the sub-matrices obtained through the division;
after said second step, a third step of transforming the received signal parts using said sub-matrices;
and
a fourth step of selecting at least one combination candidate for parts of the transmitted signals corresponding to the transformed received signals, and determining one combination candidate for each of the parts of the transmitted signals so that the determined combination candidate has a shortest Euclidean distance,
wherein the sub-matrices collectively represent all received signals as follows:
[
r
1
r
2
]
=
H
11
⁡
[
t
1
t
2
]
+
H
12
⁡
[
t
3
t
4
]
⁢
⁢
and
⁢
[
r
3
r
4
]
=
H
21
⁡
[
t
1
t
2
]
+
H
22
⁡
[
t
3
t
4
]
⁢
,
wherein each partial transmitted signal is calculated based on all received signals, where t1-t4 are transmitted signals and r1-r4 are reception signals.

162 more elements

A maximum likelihood decoding (MLD) equipment which separates and estimates multiple transmitted signals transmitted by multiple transmitter antennas from multiple received signals received by multiple receiver antennas, comprising:

a channel matrix generation unit for generating a channel matrix from channel impulse responses corresponding to the received signals;
a matrix division process unit for dividing the generated channel matrix H into multiple sub-matrices hij, in which the generated channel matrix H is defined as:
H
=
[
h
11
h
12
h
13
h
14
h
21
h
22
h
23
h
24
h
31
h
32
h
33
h
34
h
41
h
42
h
43
h
44
]
and, in which said sub-matrices hij each have a same size and are defined as:
H
11
=
[
h
11
h
12
h
21
h
22
]
⁢
⁢
H
12
=
[
h
13
h
14
h
23
h
24
]
⁢
⁢
H
21
=
[
h
31
h
32
h
41
h
42
]
⁢
⁢
and
⁢
⁢
H
22
=
[
h
33
h
34
h
43
h
44
]
.
in which said sub-matrices specify parts of the received signals corresponding to the sub-matrices obtained through the division, and transforming the sub-matrices, obtained through the division, by using inverse matrices of the sub-matrices obtained through the division;
a signal transform unit for transforming the received signal parts;
and
an MLD process unit for determining one combination candidate for each part of the transmitted signals corresponding to the transformed received signals,
wherein the sub-matrices collectively represent all received signals as follows:
[
r
1
r
2
]
=
H
11
⁡
[
t
1
t
2
]
+
H
12
⁡
[
t
3
t
4
]
⁢
⁢
and
⁢
[
r
3
r
4
]
=
H
21
⁡
[
t
1
t
2
]
+
H
22
⁡
[
t
3
t
4
]
⁢
,
wherein each partial transmitted signal is calculated based on all received signals, where t1-t4 are transmitted signals and r1-r4 are reception signals.

162 more elements

A receiver, comprising:

multiple receiver antennas for receiving multiple transmitted signals transmitted by multiple transmitter antennas;
an RF reception circuit unit for amplifying the received signals received by the receiver antennas;
and
a baseband signal processing unit for decoding the amplified received signals,
wherein the baseband signal processing unit comprises:
maximum likelihood decoding (MLD) equipment for separating and estimating the multiple transmitted signals transmitted by the multiple transmitter antennas from the amplified received signals;
a calculation unit for calculating log likelihood ratios of the multiple transmitted signals obtained through the separation;
and
a decoding unit for decoding the multiple transmitted signals obtained through the separation, based on the calculated log likelihood ratios, and
wherein the maximum likelihood decoding equipment comprises:
a channel matrix generation unit for generating a channel matrix from channel impulse responses corresponding to the received signals;
a matrix division process unit for dividing the generated channel matrix H into multiple sub-matrices hij, in which the generated channel matrix H is defined as:
H
=
[
h
11
h
12
h
13
h
14
h
21
h
22
h
23
h
24
h
31
h
32
h
33
h
34
h
41
h
42
h
43
h
44
]
and, in which said sub-matrices hij each have a same size and are defined as:
H
11
=
[
h
11
h
12
h
21
h
22
]
⁢
⁢
H
12
=
[
h
13
h
14
h
23
h
24
]
⁢
⁢
H
21
=
[
h
31
h
32
h
41
h
42
]
⁢
⁢
and
⁢
⁢
H
22
=
[
h
33
h
34
h
43
h
44
]
.
in which said sub-matrices specify parts of the received signals corresponding to the sub-matrices obtained through the division, and transforming the sub-matrices, obtained through the division, by using inverse matrices of the sub-matrices obtained through the division;
a signal transform unit for transforming the received signal parts;
and
an MLD process unit for determining one combination candidate for parts of the transmitted signals corresponding to the transformed received signals,
wherein the sub-matrices collectively represent all received signals as follows:
[
r
1
r
2
]
=
H
11
⁡
[
t
1
t
2
]
+
H
12
⁡
[
t
3
t
4
]
⁢
⁢
and
⁢
[
r
3
r
4
]
=
H
21
⁡
[
t
1
t
2
]
+
H
22
⁡
[
t
3
t
4
]
⁢
,
wherein each partial transmitted signal is calculated based on all received signals, where t1-t4 are transmitted signals and r1-r4 are reception signals.

172 more elements

Dependencies are inferred from the claim text.