Multi-access communication system

Patent metadata

Field	Value
Publication number	US-10594425-B2
Application number	US-201715497188-A
Country	US
Kind code	B2
Filing date	Apr 25, 2017
Priority date	Sep 21, 2012
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

A multiple access slotted wireless communication system comprising a plurality of terminals and a multi-access receiver is described. The multi-access receiver can decode multiple transmissions in each slot of a frame from terminals in its field of view. Each terminal has an active state for transmitting and an inactive state. After receiving acknowledgement of a successful transmission by the terminal, the terminal enters the inactive state for at least a transmission delay time. This may be the remaining time that the terminal is in the field of view of the multi-access receiver. This may be achieved by the terminal using a probability of transmission to determine whether or not to transmit in the next frame. The terminal may also be configured to select the slot in a frame, and this may be based upon information such as which slots were acknowledged. The receiver may use compression to transmit acknowledgement messages.

First claim

The invention claimed is:

1. A method for optimizing a network parameter in a set of network parameters in a multiple access wireless communication system comprising a plurality of terminals and a multi-access receiver which communicates using a frame comprising a plurality of slots, wherein each terminal has an active state for transmitting, and an inactive state during which the terminal is prevented from transmitting, and stores a probability of transmission p which, during an active state, the terminal uses to determine whether to transmit in a frame, and the multi-access receiver has a first field of view and is configured to successfully decode up to m transmissions in each slot of a frame from terminals in the field of view, wherein the network parameters comprise (p, n, m, ε) where p is the probability of an active terminal deciding to transmit in a frame when in the active state, n is the number of slots per frame, m is the number of simultaneous transmissions that a multiuser can successfully decode in a single slot, and ε is the probability of failure of a terminal to successfully transmit a message whilst in a field of view of the multiple access receiver, and the method of optimising a network parameter comprising:
selecting the network parameter and numerically solving q=1−pQ(m,λ) and

K
0

=

1
-

ɛ

1
/
F

1
-
ɛ

⁢

λ
*

⁢
n

to optimise λ* where 1−q is the proportion of terminals that succeed in transmitting in a frame and Q is the gamma function, K 0 is the number of new terminals that enter the field of view each frame, F is the number of frames a terminal is in the field of view for, λ=k/n and k=pK and where K is the number of active terminals in the field of view; and
updating the optimized network parameter in at least one of the multi-access receiver and the plurality of terminals.

2. The method as claimed in claim 1 , wherein the method is performed by the receiver and the receiver transmits changes to the system parameters to the plurality of terminals.

3. The method as claimed in claim 1 , wherein the method is performed as distributed optimization method in each of the plurality of terminals.

4. The method as claimed in claim 3 , wherein the receiver transmits K the number of active terminals in the field of view to the terminals.

5. The method as claimed in claim 3 , wherein each terminal estimates K, the number of active terminals in the field of view by counting the number of acknowledgement messages transmitted during a frame.

6. The method as claimed in claim 1 , wherein the transmission probability depends upon the number of failed transmission attempts.

7. A multi-access receiver for use in a multiple access wireless communication system comprising:
a plurality of terminals; and
a multi-access receiver,
wherein each terminal comprises:
a transmitter configured to transmit a message during a slot of a frame to the multi-access receiver when in an active state,
a memory, and
a terminal processor,
wherein when the terminal is in an active state the transmitter is permitted to transmit a message and when the terminal is in an inactive state the transmitter is prevented from transmitting, and the memory configured to store a probability of transmission p which during an active state, the terminal processor uses to determine whether to transmit in a frame; and

the multi-access receiver comprises:
a receiver for simultaneously receive m transmissions in each slot of a frame, and
a multiuser decoder for decoding the received transmissions; and
a multi-access receiver processor,
wherein the multi-access receiver processor is configured to perform a method for optimizing a network parameter in a set of network parameters, wherein the network parameters comprise (p, n, m, ε) where p is the probability of an active terminal deciding to transmit in a frame, n is the number of slots per frame, m is the number of simultaneous transmissions that a multiuser can successfully decode in a single slot, and ε is the probability of failure of a terminal to successfully transmit a message whilst in a field of view of the multiple access receiver, and the method of optimising a network parameter comprising:
selecting the network parameter and numerically solving q=1−pQ(m,λ) and

K
0

=

1
-

ɛ

1
/
F

1
-
ɛ

⁢

λ
*

⁢
n

to optimise λ* where 1−q is the proportion of terminals that succeed in transmitting in a frame and Q is the gamma function, K 0 is the number of new terminals that enter the field of view each frame, F is the number of frames a terminal is in the field of view for, λ=k/n and k=pK and where K is the number of active terminals in the field of view; and
transmit transmitting the optimized network parameter to the plurality of terminals.

8. The multi-access receiver as claimed in claim 7 wherein the transmission probability depends upon the number of failed transmission attempts.

9. A terminal for use in a multiple access wireless communication system comprising:
a plurality of terminals; and
a multi-access receiver comprising:
a receiver for simultaneously receive m transmissions in each slot of a frame; and
a multiuser decoder for decoding the received transmissions,

wherein each terminal comprises:
a transmitter configured to transmit a message during a slot of a frame to the multi-access receiver when in an active state;
a memory; and
a processor,
wherein the processor is configured to control the mode of operation of the terminal, and when the terminal is in an active state the terminal is permitted to transmit a message and when the terminal is in an inactive state the transmitter is prevented from transmitting, and the memory stores a probability of transmission p which during an active state, the processor uses to determine whether to transmit in a frame, and
the processor is further configured to perform a method for optimizing a network parameter in a set of network parameters, wherein the network parameters comprise (p, n, m, ε) where p is the probability of an active terminal deciding to transmit in a frame, n is the number of slots per frame, m is the number of simultaneous transmissions that a multiuser can successfully decode in a single s

Assignees

• Univ South Australia
• Myriota Pty Ltd

Inventors

• Grant Alexander James
• Haley David Victor Lawrie
• Mckilliam Robert George
• Cowley William George
• Chan Ho Leung

Classifications

• H04W52/02

  Power saving arrangements · CPC title

• H04B7/212

  Time-division multiple access {[TDMA]} · CPC title

• H04W52/0216

  using a pre-established activity schedule, e.g. traffic indication frame · CPC title

• H04W52/028

  switching on or off only a part of the equipment circuit blocks · CPC title

• G08C17/02

  using a radio link · CPC title