MIMO BASED NETWORK CODING NETWORK

• US 20090067533A1
• Filed: 08/27/2008
• Published: 03/12/2009
• Est. Priority Date: 08/27/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Yuan, Jun, Wu, Jianming, Tong, Wen, Fong, Mo-Han
• Granted Patent: US 8,228,835 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04B 7/15521 combining by calculations packets received from different stations before transmitting the combined packets as part of network coding network coding aspects for detection or prevention of errors in the information received H04L1/0076; network traffic management with optimizing of information sizing, e.g. header compression, by using assembly and disassembly of packets H04W28/065

Abstract

A wireless communication system includes an intermediate node, a first node and a second node. There is described a method for implementing MIMO based network coding, comprising the first node transmitting first data to the intermediate node, and the second node transmitting second data to the intermediate node. Both the first node and the second node may use spatial multiplexing or time division multiplexing or frequency division multiplexing on a common/different resource. The intermediate node receives the transmissions from the first node and second node, and performs network coding on the first data and second data using a predefined network coding scheme to produce network coded information. The intermediate node transmits the network coded information to the first node and second node using multi-user MIMO; and; each first or second node receives the MIMO transmissions from the intermediate node and applies network decoding procedures to recover the first data and second data. Network coding schemes include Decode and Forward (DF), Map and Forward (MF) and Amplify and Forward (AF). The first node and second node may be members of groups of nodes all within the same coverage area. A method for scheduling MIMO-based network coded transmissions is also described. Hybrid Automatic Repeat Request (HARQ) transmission may also be network encoded.

Claims

1. In a wireless communication system including an intermediate node, a first node and a second node, the intermediate node including a plurality of antennas, a method for implementing MIMO based network coding comprising:

the first node transmitting first data to the intermediate node, and the second node transmitting second data to the intermediate node;

the intermediate node receiving the transmissions from both first node and second node, and performing network coding on the first data and second data using a predefined network coding scheme to produce network coded information;

the intermediate node transmitting the network coded information to the first node and second node using multi-user MIMO; and

;

both first node and second node receiving the MIMO transmission and applying network decoding to recover the first data and second data.

2. The method of claim 1 wherein the MIMO transmission is a spatial multiplex transmission.

3. The method of claim 1 wherein the first node transmits first data to the intermediate node, and the second node transmits second data to the intermediate node using one or more of spatial multiplexing, time division multiplexing, and frequency division multiplexing.

4. The method of claim 1 wherein the first node transmits first data to the intermediate node, and the second node transmits second data to the intermediate node using adaptive virtual MIMO.

5. The method of claim 1 wherein the first node belongs to a group of nodes all within a same coverage area.

6. The method of claim 1 wherein the second node belongs to a group of nodes all within a same coverage area.

7. The method of claim 1 wherein network coding is implemented at the intermediate node by exclusive OR (XOR) operating the first data with the second data.

8. The method of claim 1 wherein the network coding scheme employed at the intermediate node is one of Decode and Forward (DF), Map and Forward (MF), and Amplify and Forward (AF).

9. The method of claim 1 wherein the intermediate node is one of a Relay Station (RS), Mobile Station (MS), and Base Station (BS).

10. A scheduler for scheduling MIMO-based network coded transmissions implemented in accordance with the method of claim 1, the scheduler comprising:

a first queue for storing one or more packets from the first node;

a second queue for storing one or more packets from the second node;

wherein a higher priority for scheduling of packets for network encoding is given to which one of the first queue and the second queue has a shorter queue length.

11. The method of claim 1 wherein the network coded information is a Hybrid Automatic Repeat Request (HARQ) message.

12. A transceiver in a wireless communications network for implementing MIMO based network coding, comprising:

a plurality of antennas;

circuitry operable to;

receive first data from a first node, and second data from a second node;

perform network coding on the first data and second data using a predefined network coding scheme to produce network coded information; and

transmit the network coded information to the first node and second node using multi-user MIMO.

13. The transceiver of claim 12 wherein the multi-user MIMO transmission is a spatial multiplex transmission.

14. The transceiver of claim 12 wherein the first node transmits first data to the intermediate node, and the second node transmits second data to the intermediate node using one or more of spatial multiplexing, time division multiplexing, and frequency division multiplexing.

15. The transceiver of claim 12 wherein network coding is implemented by exclusive OR (XOR) operating the first data with the second data.

16. The transceiver of claim 12 wherein the network coding scheme is one of Decode and Forward (DF), Map and Forward (MF), and Amplify and Forward (AF).

17. The transceiver of claim 12 wherein the transceiver is a Relay Station (RS) or a Mobile Station (MS).

18. The transceiver of claim 12 wherein the transceiver is a Base Station (BS).

19. The transceiver of claim 12 further comprising a scheduler, the scheduler comprising:

a first queue for storing one or more packets from the first node;

a second queue for storing one or more packets from the second node;

wherein a higher priority for scheduling of packets for network encoding is given to which one of the first queue and the second queue has a shorter queue length.

20. The transceiver of claim 12 wherein the network coded information is a Hybrid Automatic Repeat Request (HARQ) message.