METHOD FOR RESOURCE ALLOCATION IN A WIRELESS COMMUNICATION NETWORK, METHOD FOR ERROR-FREE TRANSMISSION OF INFORMATION, NODE AND WIRELESS COMMUNICATION NETWORK

• US 20120134317A1
• Filed: 11/23/2011
• Published: 05/31/2012
• Est. Priority Date: 11/25/2010
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Weitkemper, Petra, Taoka, Hidekazu
• Granted Patent: US 8,711,682 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 1/1825 Adaptation of specific ARQ protocol parameters according to transmission conditions
• CPC Class Codes: H04L 2001/0097 Relays

Abstract

An approach for resource allocation in a wireless communication network including a sender, a relay station and a receiver in case of a retransmission of information from the relay station to the receiver is described, wherein a resource necessary for retransmission is determined on the basis of the relayed channel and the relay function.

Claims

1. A method for resource allocation in a wireless communication network comprising a sender, a relay station and a receiver in case of a retransmission of information from the relay station to the receiver, the method comprising:

determining a resource necessary for retransmission based on the relayed channel and the relay function.

2. The method of claim 1, wherein the resource is determined at the relay station or at any other node in the wireless communication network, wherein in case the resource is determined at any other node in the wireless communication network, the method further comprises signaling the resource for the retransmission to the relay station.

3. The method of claim 1, wherein the sender is configured to send a codeword to the receiver, wherein retransmission is requested in case the receiver falsely decodes the codeword, and wherein the information is retransmitted to the receiver from the relay station to decode the codeword after the retransmission with a predefined probability at the receiver.

4. The method of claim 3, wherein the relayed channel comprises at least one of the channel between the sender and the receiver, the channel between the sender and the relay station, and the channel between the relay station and the receiver.

5. The method of claim 1, further comprising signaling to the node where the resource is determined one or more parameters that may be used for determining the resource.

6. The method of claim 5, wherein the parameter that may be used comprises one or more of the signal-to-noise ratios for the channels between the sender, the receiver and the relay station, and wherein a signal-to-noise ratio is signaled to the node in case it cannot be determined at the node.

7. The method of claim 1, wherein the relayed channel is typified on the basis of a channel quality.

8. The method of claim 7, wherein the channel quality is determined on the basis of the mutual information, the probability density function or the log-likelihood ratio of the relayed channel.

9. The method of claim 1, wherein the relay function comprises a detect-and-forward function, a decode-and-forward function, an estimate-and-forward function, or an amplifier-and-forward function.

10. The method of claim 1, wherein the codeword is transmitted using the hybrid automatic repeat request, and wherein the resource is the number of bits or the power for retransmission by the relay station.

11. The method of claim 10, wherein chase combining for retransmission of parts of the initially transmitted bits or incremental redundancy for retransmission of different bits of the original codeword is used.

12. The method of claim 11, wherein the relayed channel comprises the channels between the sender and the relay station, between the sender and the receiver, and between the relay station and the receiver, each channel being described by its signal-to-noise-ratio,

wherein the ratio of the number of bits for the retransmission over the number of bits for the initial transmission is as follows:

in case of IR;

p>

(R_c−

f(SNR_SD)/f(SNR_SR,SNR_RD),

in case of CC;

p>

(R_c−

f(SNR_SD)/f(SNR_SR,SNR_SD,SNR_RD)−

f(SNR_SD))

with;

p=the ratio of the number of bits for the retransmission over the number of bits for the initial transmission,

R_c=the code rate,

SNR_RD=the signal-to-noise-ratio for the channel between the sender and the receiver,

SNR_SR=the signal-to-noise-ratio for the channel between the sender and the relay station,

SNR_RD=the signal-to-noise-ratio for the channel between the relay station and the receiver, and

f(SNR)=function describing the mutual information depending on the SNR value of one or more channels.

13. A method for error-free transmission of information between the sender and a receiver of a wireless communication network, the wireless communication network further comprising a relay station, the method comprising:

transmitting a codeword from the sender to the receiver,

in case the codeword is falsely detected at the receiver, requesting a retransmission of information from the relay station,

allocating the resource for retransmission by the relay station in accordance with a method for resource allocation in a wireless communication network comprising a sender, a relay station and a receiver in case of a retransmission of information from the relay station to the receiver, said method comprising;

determining a resource necessary for retransmission based on the relayed channel and the relay function, and

performing the retransmission using the allocated resource from the relay station to the receiver to enable the receiver to decode the codeword after the retransmission with the predefined probability.

14. A computer program product comprising a program comprising instructions stored by a computer-readable medium, the instructions executing a method for resource allocation in a wireless communication network comprising a sender, a relay station and a receiver in case of a retransmission of information from the relay station to the receiver, said method comprising:

determining a resource necessary for retransmission based on the relayed channel and the relay function,

when running the program on a computer.

15. A node in a wireless communication network comprising a sender, a relay station and a receiver, the node comprising:

a processor configured to allocate a resource in case of a retransmission from the relay station to the receiver, wherein the processor is configured to determine the resource necessary for retransmission based on the relayed channel and the relay function.

16. A wireless communication network, comprising:

a sender;

a receiver configured to receive a codeword from the sender and to request a retransmission in case the codeword is falsely detected; and

a relay station configured to cause a retransmission of information in case the receiver falsely decoded the codeword,

wherein at least one of the sender, the receiver and the relay station is configured as a node in a wireless communication network comprising a sender, a relay station and a receiver, the node comprising;

a processor configured to allocate a resource in case of a retransmission from the relay station to the receiver, wherein the processor is configured to determine the resource necessary for retransmission based on the relayed channel and the relay function.