Antenna division multiple access

• US 7,630,349 B2
• Filed: 03/07/2005
• Issued: 12/08/2009
• Est. Priority Date: 03/05/2004
• Status: Expired due to Fees

• Current Assignee: Ramot at Tel Aviv University Limited (Tel Aviv University)
• Original Assignee: Ramot at Tel Aviv University Limited (Tel Aviv University)
• Inventors: Freedman, Avraham, Atzmon, Yoav
• Primary Examiner(s): Kincaid; Lester
• Assistant Examiner(s): SAMS, MATTHEW C
• Application Number:
  US11/072,339
• Publication Number:
  US 20050195784A1
• Time in Patent Office: 1,737 Days
• Field of Search: 375/267, 375/299, 370/338
• US Class Current: 370/338
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

Three or more nodes, each with a plurality of antennas, communicate by transmitting messages simultaneously to each other. One of the nodes transmits two messages to two different destination nodes using different sets of its antennas. A receiving node receives at least two of the messages as a received signal, and uses a spatial demultiplexing algorithm such as VBLAST to extract from the received signal at least one message for which the receiving node is a destination node. Before the messages are transmitted, it is decided how many of its antennas each node is allowed to use to transmit each of its messages. For that purpose, the nodes exchange RTSs (Request To Send messages) and CTSs (Clear To Send messages). Collisions among the nodes are resolved. A transmission power and a route are selected for each message.

Claims

1. A method of communication among at least three nodes, each node including a plurality of antennas, the method comprising the steps of:

(a) each of at least one transmitting node transmitting a first respective message to a destination node of said first respective message, using at least one antenna of said each transmitting node;

(b) one of said at least one transmitting node transmitting a second message to a destination node of said second message, using at least one other antenna of said one transmitting node, said destination node of said second message being different from said destination node of said first message;

wherein all said transmitting is effected simultaneously;

(c) at one of said nodes;

(i) receiving at least two said messages as a received signal; and

(ii) extracting, from said received signal, at least one of said messages for which said one node is a destination node, said extracting being effected using a spatial demultiplexing algorithm; and

(d) prior to said transmitting, deciding, for each said node that is a source node, how many of the antennas thereof said each source node is allowed to use for transmitting each said message that said each source node seeks to transmit, said deciding being effected by steps including;

(i) each said source node broadcasting, for each said message that said each source node desires to transmit, a request for a desired number of antennas for transmitting said each message;

(ii) each said node, that receives at least one said request, broadcasting, for each said at least one request, a corresponding number of antennas allowed for transmission by said each source node; and

(iii) each said source node adjusting said at least one desired number of antennas thereof in accordance with said at least one allowed number of antennas that is received by said each source node.

2. The method of claim 1, wherein said spatial demultiplexing algorithm is a VBLAST algorithm.

3. The method of claim 1, wherein each said source node broadcasts, for each said message that said each source node desires to transmit, a training set.

4. The method of claim 1, further comprising the step of:

(e) resolving collisions among the nodes.

5. The method of claim 1, further comprising the step of:

(d) for each said message, selecting a corresponding transmission power.

6. The method of claim 5, wherein said selecting of said transmission powers is effected in a manner that equalizes minimum signal-to-interference ratios of all said destination nodes.

7. The method of claim 1, wherein said requests for said desired numbers of antennas are broadcast in respective RTSs and wherein said allowed numbers of antennas are broadcast in respective CTSs.

8. A method of communication among at least three nodes, each node including a plurality of antennas, the method comprising the steps of:

(a) each of at least two transmitting nodes simultaneously transmitting a respective message to a common destination node, using at least one antenna of said each transmitting node; and

(b) said common destination node;

(i) receiving said messages as a received signal using at least as many of the antennas of said common destination node as a total number of antennas that are used by said at least two transmitting nodes to transmit said messages, and

(ii) extracting at least one of said messages from said received signal using a spatial demultiplexing algorithm; and

(c) prior to said transmitting, deciding, for each said node that is a source node, how many of the antennas thereof said each source node is allowed to use for transmitting each said message that said each source node seeks to transmit, said deciding being effected by steps including;

(i) each said source node broadcasting, for each said message that said each source node desires to transmit, a request for a desired number of antennas for transmitting said each message;

(ii) each said node, that receives at least one said request, broadcasting, for each said at least one request, a corresponding number of antennas allowed for transmission by said each source node;

(iii) each said source node adjusting said at least one desired number of antennas thereof in accordance with said at least one allowed number of antennas that is received by said each source node.

9. The method of claim 8, wherein said requests for said desired numbers of antennas are broadcast in respective RTSs and wherein said allowed numbers of antennas are broadcast in respective CTSs.

10. A method of communication among at least three nodes, each node including a plurality of antennas, the method comprising the steps of:

(a) each of at least one transmitting node transmitting a first respective message to a destination node of said first respective message, using at least one antenna of said each transmitting node, said destination node of said first respective message being different from said each transmitting node;

(b) one of said at least one transmitting node transmitting a second message to a destination node of said second message, using at least one other antenna of said one transmitting node, said destination node of said second message being different from said destination node of said first message, said destination node of said second message being different from said one transmitting node;

wherein all said transmitting is effected simultaneously;

(c) at one of said nodes;

(i) receiving at least two said messages as a received signal; and

(ii) extracting, from said received signal, at least one of said messages for which said one node is a destination node, said extracting being effected using a spatial demultiplexing algorithm; and

(d) for each said message, selecting, from among a plurality of routes from a source node of said each message to a destination node of said each message, at least one said route including a node other than said source node of said each message and said destination node, a respective route from said source node of said each message to said destination node of said each message;

wherein, for each said message said respective route is selected to minimize a metric related to interference of nodes other than said transmitting node that transmits said each message and said destination node of said each message; and

wherein said metric includes a sum of a cost of hard blockages along said respective route and a cost of soft blockages along said respective route.

11. A method of communication among at least three nodes, each node including a plurality of antennas, the method comprising the steps of:

(a) each of at least two transmitting nodes simultaneously transmitting a respective message to a common destination node, using at least one antenna of said each transmitting node, said common destination node being different from any of said at least two transmitting nodes; and

(b) said common destination node;

(i) receiving said messages as a received signal using at least as many of the antennas of said common destination node as a total number of antennas that are used by said at least two transmitting nodes to transmit said messages, and

(ii) extracting at least one of said messages from said received signal using a spatial demultiplexing algorithm; and

(c) for each said message, selecting, from among a plurality of routes from a source node of said each message to said common destination node, at least one said route including a node other than said source node of said each message and said common destination node, a respective route from said source node of said each message to said common destination node;

wherein, for each said message said respective route is selected to minimize a metric related to interference of nodes other than said transmitting node that transmits said each message and said common destination node; and

wherein said metric includes a sum of a cost of hard blockages along said respective route and a cost of soft blockages along said respective route.

12. A method of communication among at least three nodes of an ad hoc network, each node including a plurality of antennas, the method comprising the steps of:

(a) each of at least one transmitting node transmitting a first respective message to a destination node of said first respective message, using at least one antenna of said each transmitting node;

(b) one of said at least one transmitting node transmitting a second message to a destination node of said second message, using at least one other antenna of said one transmitting node, said destination node of said second message being different from said destination node of said first message;

wherein all said transmitting is effected simultaneously during a time slot;

(c) at one of said nodes;

(i) receiving at least two said messages as a received signal; and

(ii) extracting, from said received signal, at least one of said messages for which said one node is a destination node, said extracting being effected using a spatial demultiplexing algorithm; and

(d) prior to said transmitting, deciding, for each said node that is a source node, how many of the antennas thereof said each source node is allowed to use for transmitting each said message that said each source node seeks to transmit, said deciding being effected by steps including;

(i) each said source node broadcasting, for each said message that said each source node desires to transmit, a respective request for a desired number of antennas for transmitting said each message;

(ii) each said node, that receives at least one said request, broadcasting, for each said at least one request, a corresponding allowed number of antennas;

(iii) each said source node adjusting said at least one desired number of antennas thereof in accordance with said at least one allowed number of antennas that is received by said each source node;

(iv) allocating a plurality of request mini-slots, at a start of said time slot; and

(v) allocating a plurality of response mini-slots, immediately following said plurality of request mini-slots;

such that each said source node broadcasts each said respective request thereof during one of said request mini-slots and each said node that receives at least one said request broadcasts each said corresponding allowed number of antennas during one of said response mini-slots;

wherein, for each said source node, for each said respective request that is broadcast by said each source node, said request mini-slot, during which said each source node broadcasts said each respective request, is selected randomly; and

wherein, for each said node that receives at least one said request, for each said corresponding allowed number of antennas, said response mini-slot, during which said each node that receives at least one said request broadcasts said each corresponding allowed number of antennas, is selected randomly; and

wherein a number of said request mini-slots and a number of said response mini-slots are selected, according to a number of said nodes that are within transmission range, so that a probability of every said request being received by all nodes within transmission range of said node that broadcasts said request is at least a predetermined value and so that a probability of every said allowed number of antennas being received by all nodes within transmission range of said node that broadcasts said allowed number of antennas is at least said predetennined value.

13. The method of claim 12, wherein said requests for said desired numbers of antennas are broadcast in respective RTSs, wherein said allowed numbers of antennas are broadcast in respective CTSs.

14. A method of communication among at least three nodes, each node including a plurality of antennas, the method comprising the steps of:

(a) each of at least one transmitting node transmitting a first respective message to a destination node of said first respective message, using at least one antenna of said each transmitting node;

(b) one of said at least one transmitting node transmitting a second message to a destination node of said second message, using at least one other antenna of said one transmitting node, said destination node of said second message being different from said destination node of said first message;

wherein all said transmitting is effected simultaneously;

(c) at one of said nodes;

(i) receiving at least two said messages as a received signal; and

(ii) extracting, from said received signal, at least one of said messages for which said one node is a destination node, said extracting being effected using a spatial demultiplexing algorithm;

(d) prior to said transmitting, deciding, for each said node that is a source node, how many of the antennas thereof said each source node is allowed to use for transmitting each said message that said each source node seeks to transmit; and

(e) resolving collisions among the nodes by steps including;

(i) partitioning the nodes among a plurality of chains of decreasing desired numbers of transmitting antennas, each said chain including a final node; and

(ii) forbidding said final nodes to transmit.

15. A method of communication among at least three nodes, each node including a plurality of antennas, the method comprising the steps of:

(a) each of at least two transmitting nodes simultaneously transmitting, during a time slot, a respective message to a common destination node, using at least one antenna of said each transmitting node; and

(b) said common destination node;

(i) receiving said messages as a received signal using at least as many of the antennas of said common destination node as a total number of antennas that are used by said at least two transmitting nodes to transmit said messages, and

(ii) extracting at least one of said messages from said received signal using a spatial demultiplexing algorithm; and

(c) prior to said transmitting, deciding, for each said node that is a source node, how many of the antennas thereof said each source node is allowed to use for transmitting each said message that said each source node seeks to transmit, said deciding being effected by steps including;

(i) each said source node broadcasting, for each said message that said each source node desires to transmit, a respective request for a desired number of antennas for transmitting said each message;

(ii) each said node, that receives at least one said request, broadcasting, for each said at least one request, a corresponding allowed number of antennas;

(iii) each said source node adjusting said at least one desired number of antennas thereof in accordance with said at least one allowed number of antennas that is received by said each source node;

(iv) allocating a plurality of request mini-slots, at a start of said time slot; and

(v) allocating a plurality of response mini-slots, immediately following said plurality of request mini-slots;

such that each said source node broadcasts each said respective request thereof during one of said request mini-slots and each said node that receives at least one said request broadcasts each said corresponding allowed number of antennas during one of said response mini-slots;

wherein, for each said source node, for each said respective request that is broadcast by said each source node, said request mini-slot, during which said each source node broadcasts said each respective request, is selected randomly; and

wherein, for each said node that receives at least one said request, for each said corresponding allowed number of antennas, said response mini-slot, during which said each node that receives at least one said request broadcasts said each corresponding allowed number of antennas, is selected randomly; and

wherein a number of said request mini-slots and a number of said response mini-slots are selected, according to a number of said nodes that are within transmission range, so that a probability of every said request being received by all nodes within transmission range of said node that broadcasts said request is at least a predetermined value and so that a probability of every said allowed number of antennas being received by all nodes within transmission range of said node that broadcasts said allowed number of antennas is at least said predetermined value.

16. The method of claim 15, wherein said requests for said desired numbers of antennas are broadcast in respective RTSs and wherein said allowed numbers of antennas are broadcast in respective CTSs.

17. A method of communication among at least three nodes, each node including a plurality of antennas, the method comprising the steps of:

(a) each of at least two transmitting nodes simultaneously transmitting a respective message to a common destination node, using at least one antenna of said each transmitting node; and

(b) said common destination node;

(i) receiving said messages as a received signal using at least as many of the antennas of said common destination node as a total number of antennas that are used by said at least two transmitting nodes to transmit said messages, and

(ii) extracting at least one of said messages from said received signal using a spatial demultiplexing algorithm; and

(c) prior to said transmitting, deciding, for each said node that is a source node, how many of the antennas thereof said each source node is allowed to use for transmitting each said message that said each source node seeks to transmit; and

(d) resolving collisions among the nodes by steps including;

(i) partitioning the nodes among a plurality of chains of decreasing desired numbers of transmitting antennas, each said chain including a final node; and

(ii) forbidding said final nodes to transmit.