Method and architecture for wireless communication networks using cooperative relaying
First Claim
1. A method of performing communication in a wireless communication network using cooperative relaying, wherein a transmitter, a receiver and a plurality of relay stations are engaged in a communication session, and each relay station forwards signals from a first link between the transmitter and the relay station to a second link between the relay stations and the receiver, wherein each relay station forwards the signal with the use of a relative transmission parameter specific for each relay station, said relative transmission parameter being determined locally in each relay station and at least partly based on a characterization of radio transmission conditions for that relay station, and the use of at least one common transmission parameter, and wherein the common transmission parameter is at least partly based on a measure of the total communication quality between the transmitter and a receiver of a mobile station.
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Abstract
The present invention relates to wireless networks using cooperative relaying which in a communication session involve more than one relay station. In the method according to the present invention, a transmitter 210′, a receiver 220′ and at least one relay station 215 are engaged in a communication session. The relay station 215 forwards signals from a first link between the transmitter 210′ and the relay station 215 to a second link between the relay stations 215 and the receiver 220′. The relay station 215 forwards the signal with the use of a relative transmission parameter and optionally a common transmission parameter. The relative transmission parameter is determined locally in each relay station 215 and based on a characterization of a first link, or the second link or a combination of the first and second link.
48 Citations
42 Claims
- 1. A method of performing communication in a wireless communication network using cooperative relaying, wherein a transmitter, a receiver and a plurality of relay stations are engaged in a communication session, and each relay station forwards signals from a first link between the transmitter and the relay station to a second link between the relay stations and the receiver, wherein each relay station forwards the signal with the use of a relative transmission parameter specific for each relay station, said relative transmission parameter being determined locally in each relay station and at least partly based on a characterization of radio transmission conditions for that relay station, and the use of at least one common transmission parameter, and wherein the common transmission parameter is at least partly based on a measure of the total communication quality between the transmitter and a receiver of a mobile station.
- 8. A method of performing communication in a wireless communication network using cooperative relaying, wherein a transmitter, a receiver and a plurality of relay stations are engaged in a communication session, and each relay station forwards signals from a first link between the transmitter and the relay station to a second link between the relay stations and the receiver, wherein each relay station forwards the signal with the use of a relative transmission parameter specific for each relay station, said relative transmission parameter being determined locally in each relay station and at least partly based on a characterization of radio transmission conditions for that relay station, and the use of at least one common transmission parameter, and wherein the common transmission parameter is at least partly based on a measure of the total communication quality between the transmitter and a receiver of a mobile station, and wherein the at least one common transmission parameter comprises a relay activation threshold, which is multicasted from the receiver to the relay stations and said relay activation threshold specifies, conditions which the relay stations must fulfill in order to be active in the forwarding of the signal on the second link.
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14. A method of performing communication in a wireless communication network using cooperative relaying, wherein a transmitter, a receiver and a plurality of relay stations are engaged in a communication session, and each relay station forwards signals from a first link between the transmitter and the relay station to a second link between the relay stations and the receiver, wherein each relay station forwards the signal with the use of a relative transmission parameter specific for each relay station, said relative transmission parameter being determined locally in each relay station and at least partly based on a characterization of radio transmission conditions for that relay station, and the use of at least one common transmission parameter, and wherein the common transmission parameter is at least partly based on a measure of the total communication quality between the transmitter and a receiver of a mobile station,
wherein the method further comprises the steps of: -
sending pilots on k paths of link 1, from transmitter to the relay stations, and on the k paths of link 2, from the receiver to the relay stations; estimating in each relay station the k channel of link 1, h1,k and the k channel of link 2, h2,k; determining in each relay station a relative transmission parameter or a set of relative transmission parameters, wherein the relative parameter is based on one, or both, of the channel estimates h1,k, h2,k characterizing each path; determining in the receiver the common transmission parameter, or a set of common transmission parameters, based on the total communication quality experienced by the receiver; broadcasting by the receiver the common transmission parameter(s) to the relay stations; using in each relay station the relay station'"'"'s respective relative transmission parameter and the common transmission parameter(s) to adapt the subsequent transmissions on link 2; and wherein the step of using the relay station'"'"'s respective relative transmission parameter and the common transmission parameter(s) to adapt the subsequent transmissions on link 2, comprises to, on reception of signal yk, transmitting the signal;
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18. A system adapted for communication in a wireless communication network using cooperative relaying, the system comprises a transmitter, a receiver and at least one relay station, wherein the relay station is adapted to forward signals from a first link between the transmitter and the relay station to a second link between the relay stations and the receiver, said system has a logical architecture wherein:
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at least one relay station has means for performing channel characterization and means for determining relative transmission parameters based on channel characterization and means for adapting the forwarding based on a common transmission parameter and a relative transmission parameter; the receiver has means for determining a common transmission parameter and means for distributing the common transmission parameter to the relay stations, wherein the common transmission parameter is at least partly based on a measure of the total communication quality between the transmitter and a receiver of a mobile station; and the logical architecture comprises a first control loop between the receiver and the relay stations adapted to feedback the common parameter from receiver to the relay stations; and wherein the relative transmission parameter is based on at least one of the following;
a characterisation of a radio path of the first link;
a characterisation of a radio path of the second link; and
a combination of the characterisation of a radio path of the first and second link. - View Dependent Claims (19, 20, 21, 22, 23, 29, 32, 33)
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24. A relay station adapted for use in a wireless communication network using cooperative relaying, wherein the relay station is adapted to forward signals from a first link between a transmitter and the relay station to a second link between the relay stations and the receiver, wherein the relay station has means for performing channel characterization and means for determining relative transmission parameters based on channel characterization and means for adapting the forwarding at least partly based on the relative transmission parameter and on a common transmission parameter previously received by the relay station, wherein the common transmission parameter is at least partly based on a measure of the total communication quality between the transmitter and a receiver of a mobile station;
- and wherein the relative transmission parameter is based on at least one of the following;
a characterisation of a radio path of the first link;
a characterisation of a radio path of the second link; and
a combination of the characterisation of a radio path of the first and second link. - View Dependent Claims (25, 26, 34, 35, 36)
- and wherein the relative transmission parameter is based on at least one of the following;
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27. A basestation adapted for use in a wireless communication network using cooperative relaying, wherein the basestation comprises a receiver, and the network comprises a plurality of relay stations, each adapted to forward signals from a first link between a transmitter and the relay station to a second link between the relay station and the receiver of the base station, wherein the receiver of the base station comprises means for determining a common transmission parameter and means for distributing the common transmission parameter to the relay stations, and wherein the common transmission parameter is at least partly based on a measure of the total communication quality between the transmitter and the receiver of the basestation.
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28. A mobile station adapted for use in a wireless communication network using cooperative relaying, wherein the mobile station comprises a receiver, and the network comprises a plurality of relay stations, each adapted to forward signals from a first link between a transmitter and the relay station to a second link between the relay station and the receiver of the mobile station, wherein the receiver comprises means for determining a common transmission parameter and means for distributing the common transmission parameter to the relay stations, and wherein the common transmission parameter is at least partly based on a measure of the total communication quality between the transmitter and the receiver of the mobile station.
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37. A method of operating a relay station in a wireless communication network using cooperative relaying, the method comprising:
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receiving first signals on a first link between a transmitter and the relay station; determining at the relay station a relative transmission parameter specific for the relay station, said relative transmission parameter being at least partly based on a characterization of radio transmission conditions for the relay station; forwarding the first signal to a second link between the relay station and a receiver with the use of the relative transmission parameter and at least one common transmission parameter, and wherein the common transmission parameter is at least partly based on a measure of the total communication quality between the transmitter and the receiver of a mobile station. - View Dependent Claims (38, 39, 40, 41, 42)
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Specification