US2010098149A1PendingUtilityA1
Systems and methods for multicarrier modulation using multi-tap frequency-domain equalizer and decision feedback
Est. expiryAug 2, 2021(expired)· nominal 20-yr term from priority
H04L 25/03019H04L 25/03159H04L 2025/03414H04L 2025/03522
56
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Claims
Abstract
Through the use of feedback in determining frequency domain equalization, interference can be reduced. Specifically, the determined constellation point closest to the determined received point can be fed back to aid in determining one or more other closest constellation points.
Claims
exact text as granted — not AI-modified1 . An intersymbol interference reduction system comprising:
a frequency domain equalizer; and a constellation decoder, the frequency domain equalizer determining at least one received point based at least on at least one previously determined constellation point.
2 . The system of claim 1 , wherein the at least one previously determined constellation point is feedback which can be one or more of forward looking feedback and backward looking feedback.
3 . The system of claim 1 , wherein a plurality of decisions about the value of s m 1 i 1 obtained by quantizing to the nearest constellation point are used in determining the at least one received point.
4 . The system of claim 1 , wherein a sub-channel output for the frequency domain equalizer for a subchannel m 1 and frame i 1 are determined in accordance with:
=
∑
{
m
,
j
}
∈
A
(
m
1
)
λ
j
m
(
m
1
)
θ
i
1
+
j
m
+
∑
{
m
,
j
}
∈
B
(
m
1
)
γ
j
m
(
m
1
)
d
i
1
+
j
m
where A(m 1 ) is a set containing ordered pairs {m, j} of indices corresponding to the particular subchannel, frame pairs for which the receiver transform outputs are used in the frequency domain equalizer, for subchannel m 1 , B(m 1 ) is a set containing ordered pairs {m, j} of indices corresponding to the particular subchannel, frame pairs for which decisions are used in the frequency domain equalizer for subchannel m 1 , λ j m (m 1 ) are the corresponding frequency domain equalizer weights, θ m i represents the transform output for subchannel m, in frame i, γ j m is the corresponding combiner weights and d i 1 m 1 is a value for s m 1 i 1 determined by quantizing to the nearest constellation point.
5 . The system of claim 1 , wherein the intersymbol interference reduction system is used to reduce intersymbol interference in a multicarrier communication environment.
6 . The system of claim 1 , wherein the intersymbol interference reduction system is incorporated into a transceiver.
7 . A method for reducing intersymbol interference reduction comprising:
determining at least one constellation point; and determining at least one received point based at least on at least one previously determined constellation point.
8 . The method of claim 7 , wherein the at least one previously determined constellation point is feedback which can be one or more of forward looking feedback and backward looking feedback.
9 . The method of claim 7 , wherein a plurality of decisions about the value of s m 1 i 1 obtained by quantizing to the nearest constellation point are used in determining the at least one received point.
10 . The method of claim 7 , wherein a sub-channel output for the frequency domain equalizer for a subchannel m 1 and frame i 1 are determined in accordance with:
=
∑
{
m
,
j
}
∈
A
(
m
1
)
λ
j
m
(
m
1
)
θ
i
1
+
j
m
∑
{
m
,
j
}
∈
B
(
m
1
)
γ
j
m
(
m
1
)
d
i
1
+
j
m
where A(m 1 ) is a set containing ordered pairs {m, j} of indices corresponding to the particular subchannel, frame pairs for which the receiver transform outputs are used in the frequency domain equalizer, for subchannel m 1 , B(m 1 ) is a set containing ordered pairs {m, j} of indices corresponding to the particular subchannel, frame pairs for which decisions are used in the frequency domain equalizer for subchannel m 1 , λ j m (m 1 ) are the corresponding frequency domain equalizer weights, θ m i represents the transform output for subchannel m, in frame i, γ j m is the corresponding combiner weights and d i 1 m 1 is a value for s m 1 i i determined by quantizing to the nearest constellation point.
11 . The method of claim 7 , wherein the intersymbol interference reduction method is used to reduce intersymbol interference in a multicarrier communication environment.
12 . The method of claim 7 , wherein the intersymbol interference reduction method is incorporated into a transceiver.
13 . An intersymbol interference reduction system comprising:
means for determining at least one constellation point; and means for determining at least one received point based at least on at least one previously determined constellation point.
14 . The system of claim 13 , wherein the at least one previously determined constellation point is feedback which can be one or more of forward looking feedback and backward looking feedback.
15 . The system of claim 13 , wherein a plurality of decisions about the value of s m 1 i 1 obtained by quantizing to the nearest constellation point are used in determining the at least one received point.
16 . The system of claim 13 , wherein a sub-channel output for the frequency domain equalizer for a subchannel m 1 and frame 1 1 are determined in accordance with:
=
∑
{
m
,
j
}
∈
A
(
m
1
)
λ
j
m
(
m
1
)
θ
i
1
+
j
m
∑
{
m
,
j
}
∈
B
(
m
1
)
γ
j
m
(
m
1
)
d
i
1
+
j
m
where A(m 1 ) is a set containing ordered pairs {m, j} of indices corresponding to the particular subchannel, frame pairs for which the receiver transform outputs are used in the frequency domain equalizer, for subchannel m 1 , B(m 1 ) is a set containing ordered pairs {m, j} of indices corresponding to the particular subchannel, frame pairs for which decisions are used in the frequency domain equalizer for subchannel m 1 , λ j m (m 1 ) are the corresponding frequency domain equalizer weights, θ m i represents the transform output for subchannel m, in frame i, γ j m is the corresponding combiner weights and d i 1 m 1 is a value for s m 1 i 1 determined by quantizing to the nearest constellation point.
17 . The system of claim 13 , wherein the intersymbol interference reduction method is used to reduce intersymbol interference in a multicarrier communication environment.
18 . The system of claim 13 , wherein the intersymbol interference reduction method is incorporated into a transceiver.
19 . An information storage media comprising information for reducing intersymbol interference reduction comprising:
information that determines at least one constellation point; and information that determines at least one received point based at least on at least one previously determined constellation point.
20 . The media of claim 19 , wherein the at least one previously determined constellation point is feedback which can be one or more of forward looking feedback and backward looking feedback.
21 . The media of claim 19 , wherein a plurality of decisions about the value of s m 1 i 1 obtained by quantizing to the nearest constellation point are used in determining the at least one received point.
22 . The media of claim 19 , wherein a sub-channel output for the frequency domain equalizer for a subchannel m 1 and frame i 1 are determined in accordance with:
=
∑
{
m
,
j
}
∈
A
(
m
1
)
λ
j
m
(
m
1
)
θ
i
1
+
j
m
∑
{
m
,
j
}
∈
B
(
m
1
)
γ
j
m
(
m
1
)
d
i
1
+
j
m
where A(m 1 ) is a set containing ordered pairs {m, j} of indices corresponding to the particular subchannel, frame pairs for which the receiver transform outputs are used in the frequency domain equalizer, for subchannel m 1 , B(m 1 ) is a set containing ordered pairs {m, j} of indices corresponding to the particular subchannel, frame pairs for which decisions are used in the frequency domain equalizer for subchannel m 1 , λ j m (m 1 ) are the corresponding frequency domain equalizer weights, θ m i represents the transform output for subchannel m, in frame i, γ j m is the corresponding combiner weights and d i 1 m 1 is a value for s m 1 i 1 determined by quantizing to the nearest constellation point.
23 . The media of claim 19 , wherein the intersymbol interference reduction method is used to reduce intersymbol interference in a multicarrier communication environment.
24 . The media of claim 19 , wherein the intersymbol interference reduction method is incorporated into a transceiver.Join the waitlist — get patent alerts
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