US 7,352,800 B2Granted

Method of partial parallel interference cancellation

AssigneeBenq Corporation

InventorsYih-Min Chen, Hsu-Ching Wang, Chun-Cheng Chen, Fu-Yen Kuo

Life of this patent

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Abstract

A method of Partial Parallel Interference Cancellation (PPIC) is provided for recursively eliminating the Multiple Access Interference from a received signal. Such method is to use a recursion way to eliminate all the Multiple Access Interference (MAI) one by one from the received signal. Moreover, the present invention is to take the output of the pre-stage as the input of the present stage with the recursion method so that we can use only one operating circuit to obtain the function the MAI eliminating.

Claims12

Dependent claims

A method of Partial Parallel Interference Cancellation (PPIC) for recursively eliminating Multiple Access Interference of a received signal for a receiver, including the following steps:

A:
receiving a system delay parameter and offering a recursion parameter;
B:
building a related matrix based on the system delay parameter, wherein,
ℜ
k
×
k
=
⌊
r
i
,
j
⌋
r
i
,
j
=
{
ρ
i
,
j
(
m
)
,
i
<
j
ρ
j
,
i
(
v
)
,
i
>
j
⁢
⁢
ρ
i
,
j
(
m
)
=
1
T
⁢
∫
0
T
-

τ
i
-
τ
j

⁢
a
i
⁡
(
t
)
⁢
a
j
⁡
(
t
+

τ
i
-
τ
j

)
⁢
⁢
ⅆ
t
⁢
⁢
ρ
i
,
j
(
v
)
=
1
T
⁢
∫
T
-

τ
i
-
τ
j

T
⁢
a
i
⁡
(
t
)
⁢
a
j
⁡
(
t
+

τ
i
-
τ
j

-
T
)
⁢
⁢
ⅆ
t
k means the total users in the system,
i means the ith user,
j means the jth user,
ai means the spreading codes of the ith user,
aj means the spreading codes of the jth user,
τi means the delay time of the ith user,
τj means the delay time of the jth user;
C:
computing an input parameter Zi,w(0):
Z
i
,
w
(
0
)
=
1
T
⁢
∫
wT
+
τ
i
(
w
+
1
)
⁢
T
+
τ
i
⁢
r
⁡
(
t
)
⁢
a
i
(
t
-
wT
-
τ
i
⁢
)
⁢
ⅆ
t
wherein,
Zi,w(0) means the wth bit value of the ith user,
r(t) means the received signals;
D:
setting an executive parameter equal to 1, expressed as s=1;
E:
computing a result value, which can be shown as:
Z
i
,
w
(
s
)
=
⁢
Z
i
,
w
(
0
)
-
P
s
⁢
{
∑
l
=
1
k
-
1
⁢
[
Z
l
,
w
(
s
-
1
)
⁢
ρ
i
,
l
(
m
)
+
Z
l
,
w
+
1
(
s
-
1
)
⁢
ρ
i
,
l
(
v
)
]
+
⁢
∑
l
=
k
+
1
K
⁢
[
Z
l
,
w
(
s
-
1
)
⁢
ρ
i
,
l
(
m
)
+
Z
l
,
w
-
1
(
s
-
1
)
⁢
ρ
i
,
l
(
v
)
]
}
wherein, Ps means the Partial Factor of the STAGE s;
F:
determining whether the executive parameter is the recursion parameter;
G:
If the executive parameter is the recursion parameter, then outputting
Zi,w(s) from the receiver;
H:
If the executive parameter is not the recursion parameter, then increasing 1 to the executive parameter and then executing step E.

331 more elements

Dependencies are inferred from the claim text.

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Abstract

A method of Partial Parallel Interference Cancellation (PPIC) for recursively eliminating Multiple Access Interference of a received signal for a receiver, including the following steps:

A:
receiving a system delay parameter and offering a recursion parameter;
B:
building a related matrix based on the system delay parameter, wherein,
ℜ
k
×
k
=
⌊
r
i
,
j
⌋
r
i
,
j
=
{
ρ
i
,
j
(
m
)
,
i
<
j
ρ
j
,
i
(
v
)
,
i
>
j
⁢
⁢
ρ
i
,
j
(
m
)
=
1
T
⁢
∫
0
T
-

τ
i
-
τ
j

⁢
a
i
⁡
(
t
)
⁢
a
j
⁡
(
t
+

τ
i
-
τ
j

)
⁢
⁢
ⅆ
t
⁢
⁢
ρ
i
,
j
(
v
)
=
1
T
⁢
∫
T
-

τ
i
-
τ
j

T
⁢
a
i
⁡
(
t
)
⁢
a
j
⁡
(
t
+

τ
i
-
τ
j

-
T
)
⁢
⁢
ⅆ
t
k means the total users in the system,
i means the ith user,
j means the jth user,
ai means the spreading codes of the ith user,
aj means the spreading codes of the jth user,
τi means the delay time of the ith user,
τj means the delay time of the jth user;
C:
computing an input parameter Zi,w(0):
Z
i
,
w
(
0
)
=
1
T
⁢
∫
wT
+
τ
i
(
w
+
1
)
⁢
T
+
τ
i
⁢
r
⁡
(
t
)
⁢
a
i
(
t
-
wT
-
τ
i
⁢
)
⁢
ⅆ
t
wherein,
Zi,w(0) means the wth bit value of the ith user,
r(t) means the received signals;
D:
setting an executive parameter equal to 1, expressed as s=1;
E:
computing a result value, which can be shown as:
Z
i
,
w
(
s
)
=
⁢
Z
i
,
w
(
0
)
-
P
s
⁢
{
∑
l
=
1
k
-
1
⁢
[
Z
l
,
w
(
s
-
1
)
⁢
ρ
i
,
l
(
m
)
+
Z
l
,
w
+
1
(
s
-
1
)
⁢
ρ
i
,
l
(
v
)
]
+
⁢
∑
l
=
k
+
1
K
⁢
[
Z
l
,
w
(
s
-
1
)
⁢
ρ
i
,
l
(
m
)
+
Z
l
,
w
-
1
(
s
-
1
)
⁢
ρ
i
,
l
(
v
)
]
}
wherein, Ps means the Partial Factor of the STAGE s;
F:
determining whether the executive parameter is the recursion parameter;
G:
If the executive parameter is the recursion parameter, then outputting
Zi,w(s) from the receiver;
H:
If the executive parameter is not the recursion parameter, then increasing 1 to the executive parameter and then executing step E.

331 more elements