Permutation mapping for ARQ-processed transmissions
View Patent ↗A method of communicating individual packets i of K bits includes permutation mapping of the packets, with each permuted packet being denoted by Π n (i), wherein Π n is a permutation on K letters that is unique for each packet transmission. Each permuted packet Π n (i) is modulated to provide a complex vector x(Π n (i)) for each packet. The packets are transmitted over a AWGN channel so each individual packet i is received as a variable of the vector x(Π n (i)) in a complex vector y n =x(Π n (i))+v n , wherein n represents the sequential number of the transmission attempt for a particular packet and v n represents noise. This method enables the packets to be transmitted while using an improved ARQ routine that includes soft-combining decisions and a constant constellation with a constellation complexity greater than two bits/symbol to thereby significantly improve ARQ-routine performance over the current state of the art.
1. A method of communicating individual packets i of K bits, comprising steps of:
(a) performing permutation mapping of the packets, with each permuted packet being denoted by Π n (i), wherein Π n is a permutation on K letters that is unique for each packet transmission, wherein i denotes a particular individual packet and the K letters are the positions of the K bits;
(b) modulating Π n (i) to provide a complex vector x(Π n (i)) for each packet; and
(c) transmitting the packets so that the transmission of each individual packet i is received as a variable of the complex vector x(Π n (i)) in a complex vector y n =x(Π n (i))+v n , wherein n represents the sequential number of the transmission attempt for a particular packet and v n represents noise.
2. A method according to claim 1 , wherein for a sequence of individual packets i a , i b , . . . , step (c) comprises a step of: (d) transmitting the packets so that the transmission of the sequence of individual packets i is received as y an =x(Π an (i a ))+v an , y bn =x(Π bn (i b ))+v bn , . . . .
3. A method according to claim 1 , further comprising the step of:
(d) constructing an a posteriori estimate of the packet i from a received transmission of the complex vector y n .
4. A method according to claim 3 , wherein step (d) comprises a step of:
(e) constructing an a posteriori estimate of the packet i in accordance with
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wherein k denotes a particular bit of the K bits and S 1 denotes the set of symbols where bit- 1 =1, and y is a vector with tuples from all or any subset of the received transmission of the complex vector y n .
5. A method according to claim 3 , wherein the transmission is over a complex AWGN channel, y is a vector with tuples from all or any subset of the received transmission of the complex vector y n , and step (d) comprises a step of:
(e) constructing an a posteriori estimate of the packet i in accordance with
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bit
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2
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2
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wherein σ represents the power of the noise, and S 1 denotes the set of symbols where bit- 1 =1.
6. A method according to claim 1 , wherein i is a binary vector of length K, and Π is taken from a set of permutations that does not include all of a symmetric group on K letters.
7. A method according to claim 1 performed while executing an automatic repeat request (ARQ) routine in which transmission of a particular packet is repeated automatically when correct receipt of the particular packet is not acknowledged within a timeout interval following transmission of the particular packet, wherein the ARQ routine includes soft-combining decisions and a constant constellation with a constellation complexity greater than two bits-per-symbol.
8. A system for communicating individual packets i of K bits, comprising: a computer section containing a computer and computer readable storage media that includes computer executable instructions for causing the computer to execute routines of: (a) performing permutation mapping of the packets, with each permuted packet being denoted by Π n (i), wherein Π n is a permutation on K letters that is unique for each packet transmission, wherein i denotes a particular individual packet and the K letters are the positions of the K bits; and
(b) modulating Π n (i) to provide a complex vector x(Π n (i)) for each packet; and
(c) transmitting the packets so that the transmission of each individual packet i is received as a variable of the complex vector x(Π n (i)) in a complex vector y n =x(Π n (i))+v n , wherein n represents the sequential number of the transmission attempt for a particular packet and v n represents noise.
9. A system according to claim 8 , wherein the-computer readable storage media also includes computer executable instructions for causing the computer to execute a routine of:
(d) constructing an a posteriori estimate of the packet i from a received transmission of the complex vector y n .
10. A system according to claim 9 , wherein the computer executable instructions for causing the computer to execute routine (d) are adapted for causing the computer to construct said a posteriori estimate in accordance with
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when y is a vector with tuples from all or any subset of the received transmission of the complex vector y n , wherein k denotes a particular bit of the K bits and S 1 denotes the set of symbols where bit- 1 =1, and y is a vector with tuples from all or any subset of the received transmission of the complex vector y n .
11. A system according to claim 10 , wherein the computer executable instructions for causing the computer to execute routine (d) are adapted for causing the computer to construct said a posteriori estimate in accordance with
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bit
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when the transmission is over a complex AWGN channel and y is a vector with tuples from all or any subset of the received transmission of the complex vector y n , wherein k denotes a particular bit of the K bits and S 1 denotes the set of symbols where bit- 1 =1, and y is a vector with tuples from all or any subset of the received transmission of the complex vector y n .
12. A system according to claim 8 , wherein i is a binary vector of length K, and Π is taken from a set of permutations that does not include all of a symmetric group on K letters.
13. A system according to claim 8 , wherein the computer readable storage media also includes computer executable instructions for causing the computer to execute an automatic repeat request (ARQ) routine in which transmission of a particular packet is repeated automatically when correct receipt of the particular packet is not acknowledged within a timeout interval following transmission of the particular packet, wherein the ARQ routine includes soft-combining decisions and a constant constellation with a constellation complexity greater than two bits-per-symbol.
14. A non-transitory computer readable storage medium for use with a computer in a system for communicating individual packets i of K bits, wherein the computer readable storage medium contains computer executable program instructions for causing the computer to perform steps of: (a) performing permutation mapping of the packets, with each permuted packet being denoted by Π n (i), wherein Π n is a permutation on K letters that is unique for each packet transmission, wherein i denotes a particular individual packet and the K letters are the positions of the K bits; and
(b) modulating Π n (i) to provide a complex vector x(Π n (i)) for each packet, so that the transmission of each individual packet i by the system is received as a variable of the complex vector x(Π n (i)) in a complex vector y n =x(Π n (i))+v n , wherein n represents the sequential number of the transmission attempt for a particular packet and v n represents noise.
15. A non-transitory computer readable storage medium according to claim 14 , wherein for a sequence of individual packets i a , i b , . . . , the transmission of the sequence of individual packets i is received as y an =x(Π an (i a ))+v an , y bn =x(Π bn (i b ))+v bn , . . . .
16. A non-transitory computer readable storage medium according to claim 14 , wherein the computer readable storage medium also contains computer executable program instructions for causing the computer to perform a step of:
(c) constructing an a posteriori estimate of the packet i from a received transmission of the complex vector y n .
17. A non-transitory computer readable storage medium according to claim 16 , wherein step (c) comprises a step of:
(d) constructing the a posteriori estimate of the packet i in accordance with
P
(
bit
k
=
1
|
y
)
=
∑
x
∈
S
1
,
k
P
(
x
|
y
)
when y is a vector with tuples from all or any subset of the received transmission of the complex vector y n , wherein k denotes a particular bit of the K bits and S 1 denotes the set of symbols where bit- 1 =1.
18. A non-transitory computer readable storage medium according to claim 16 , wherein step (c) comprises a step of:
(d) constructing the a posteriori estimate of the packet i in accordance with
P
(
bit
k
=
1
|
y
)
=
∑
x
∈
S
1
,
k
ⅇ
-
y
-
x
2
2
σ
2
∑
x
′
ⅇ
-
y
-
x
′
2
2
σ
2
when the transmission is over a complex AWGN channel and y is a vector with tuples from all or any subset of the received transmission of the complex vector y n ,
wherein σ represents the power of the noise and S 1 denotes the set of symbols where bit- 1 =1.
19. A non-transitory computer readable storage medium according to claim 14 , wherein i is a binary vector of length K, and Π is taken from a set of permutations that does not include all of a symmetric group on K letters.
20. A non-transitory computer readable storage medium according to claim 14 , wherein the computer readable storage medium also contains computer executable program instructions for causing the computer to perform the step of: (c) executing an automatic repeat request (ARQ) routine in which transmission of a particular packet is repeated automatically when correct receipt of the particular packet is not acknowledged within a timeout interval following transmission of the particular packet, wherein the ARQ routine includes soft-combining decisions and a constant constellation with a constellation complexity greater than two bits-per-symbol.