Cellular network based on relay station and space division duplex communication method

• US 20080013520A1
• Filed: 07/10/2007
• Published: 01/17/2008
• Est. Priority Date: 07/12/2006
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Chen, Lan, Pan, Zhengang, Liu, Jingxiu
• Granted Patent: US 7,974,240 B2
• Time in Patent Office: Days
• US Class Current: 370/347
• CPC Class Codes: H04B 7/15542 Selecting at relay station its transmit and receive resources selection of wireless resources by user or terminal H04W72/02; arrangements affording multiple use of the transmission path by two-dimensional division of the resources H04L5/0003, or by allocating sub-channels H04L5/003
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 76/20 Manipulation of established connections
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

A cellular network that is based on relay station and a space division duplex communication method are disclosed. The cellular network based on RS includes a base station, a RS and a UE, wherein the base station has at least one antenna and the RS has at least two antennas. The base station allocates resources for the UE, transmits a downlink signal in a current slot and receives an uplink signal from the UE through the RS in a next slot; the RS receives the downlink signal from the base station and the uplink signal from the UE in the current slot and transmits the received downlink signal to the UE and the uplink signal to the base station in the next slot; the UE transmits the uplink signal in the current slot and receives the downlink signal through the RS in the next slot, wherein the uplink signal and the downlink signal transmitted in the same slot are orthogonal. With the cellular network and the communication method of embodiments of the present invention, the use efficiency of each channel can be improved effectively and the system complexity can be reduced.

Claims

1. A cellular network based on relay station, comprising a base station, a relay station and a user equipment, wherein the base station has at least one antenna and the relay station has at least two antennas, wherein

the base station allocates resources for the user equipment, transmits a downlink signal in a current slot and receives an uplink signal from the user equipment through the relay station in the next slot;

the relay station receives the downlink signal from the base station and the uplink signal from the user equipment in the current slot and transmits the received downlink signal to the user equipment and the uplink signal to the base station in the next slot;

the user equipment transmits the uplink signal in the current slot and receives the downlink signal through the relay station in the next slot, and

wherein the uplink signal and the downlink signal transmitted in the same slot are orthogonal.

2. The cellular network according to claim 1, wherein after receiving the downlink signal from the base station and the uplink signal from the user equipment in the current slot, the relay station obtains corresponding beam coefficients of the downlink and the uplink signals according to pilot signals of the downlink and the uplink signals, transmits the uplink signal to the base station in the next slot using the beam coefficient of the downlink signal obtained in the current slot and transmits the downlink signal to the user equipment in the next slot using the beam coefficient of the uplink signal obtained in the current slot.

3. A space division duplex communication method, comprising:

step a, at a base station, transmitting a broadcasting signal and allocating resources for a user equipment according to a feedback signal corresponding to the broadcasting signal;

step b, transmitting a downlink signal from the base station and an uplink signal from the user equipment to a relay station in a current slot;

step c, at the relay station, transmitting the downlink signal received from the base station to the user equipment and the uplink signal received from the user equipment to the base station in the next slot,

wherein the uplink signal and the downlink signal transmitted in the same slot are orthogonal.

4. The method according to claim 3, wherein,

transmitting the downlink signal from the base station comprises the relay station further estimates beam coefficients of the downlink and the uplink signals according to pilot signals of the downlink and the uplink signals in the current slot;

and

transmitting the downlink signal at the relay station comprises the relay station transmits the uplink signal received from the user equipment to the base station in the next slot using the beam coefficient of the downlink signal obtained in the current slot and transmits the downlink signal received from the base station to the user equipment in the next slot using the beam coefficient of the uplink signal obtained in the current slot.

5. The method according to claim 3 or 4, wherein transmitting the broadcasting signal and allocating resources further comprises:

at the base station, transmitting the broadcasting signal periodically;

=at the relay station, attaching an identification information to the received broadcasting signal and transferring the broadcasting signal from the base station;

at the user equipment, feeding back the feedback signal with the identification information of the relay station covering the user equipment to the base station; and

at the base station, allocating resources for the user equipment and transmitting the allocation result to the user equipment and the corresponding relay station.

6. The method according to claim 5, wherein the identification information comprises a serial number of the relay station.

7. The method according to claim 6, wherein the feedback signal further comprises a path loss value or a SINR value of the relay station covering the user equipment.

8. A cellular network based on relay station, comprising a base station, a first relay station, a second relay station and a user equipment, wherein the base station has at least one antenna and each relay station has at least two antennas, wherein

the base station allocates resources for the user equipment, transmits a downlink signal in a current slot and receives an uplink signal from the first relay station in the next slot;

the first relay station receives the downlink signal from the base station and the uplink signal from the second relay station in the current slot and transmits the downlink signal to the second relay station and the uplink signal to the base station in the next slot;

the second relay station transmits the uplink signal to the first relay station and the downlink signal to the user equipment in the current slot and transmits the received downlink signal to the user equipment and the received uplink signal to the first relay station in the next slot;

the user equipment receives the downlink signal from the second relay station in the current slot and transmits the uplink signal in the next slot,

wherein the uplink signal and the downlink signal transmitted in the same slot are orthogonal.

9. The cellular network according to claim 8, wherein after receiving the downlink signal and the uplink signal in the current slot, the relay station obtains beam coefficients of the downlink and the uplink signals according to pilot signals of the downlink and the uplink signals, transmits the uplink signal in the next slot using the beam coefficient of the downlink signal and transmits the downlink signal in the next slot using the beam coefficient of the uplink signal.

10. A space division duplex communication method, comprising:

at a base station, transmitting a broadcasting signal and allocating resources for a user equipment according to a feedback signal corresponding to the broadcasting signal;

transmitting a downlink signal from the base station to a first relay station, and at the same time, transmitting from a second relay station an uplink signal to the first relay station and a downlink signal to a user equipment;

at the first relay station, transmitting the downlink signal received from the base station to the second relay station and the uplink signal received from the second relay station to the base station in the current slot to the base station in the next slot, and at the same time, transmitting the uplink signal from the user equipment to the second relay station,

wherein the uplink signal and the downlink signal transmitted in the same slot are orthogonal.

11. The method according to claim 10, wherein,

transmitting the downlink signal from the base station comprises the first relay station further estimates corresponding beam coefficients of the downlink and the uplink signals according to pilot signals of the downlink and the uplink signals in the current slot;

and

transmitting the downlink signal at the relay station comprises the first relay station transmits the uplink signal received from the second relay station to the base station in the next slot using the beam coefficient of the downlink signal and transmits the downlink signal from the base station to the second relay station in the next slot using the beam coefficient of the uplink signal.

12. The method according to claim 10 or 11, wherein transmitting the broadcasting signal and allocating resources further comprises:

at the base station, transmitting the broadcasting signal periodically;

at the relay station, attaching an identification information to the received broadcasting signal and transferring the broadcasting signal from the base station;

at the user equipment, feeding back the feedback signal with the identification information of the relay station covering the user equipment to the base station;

at the base station, allocating resources for the user equipment and transmitting the allocation result to the user equipment and the corresponding relay station.

13. The method according to claim 12, wherein the identification information comprises a serial number of the relay station.

14. The method according to claim 13, wherein the feedback signal further comprises a path loss value or a SINR value of the relay station covering the user equipment.

15. A cellular network based on relay station, comprising a base station, a plurality of relay stations and a user equipment, wherein the base station has at least one antenna and each relay station has at least two antennas, wherein

at least one relay station among the plurality of relay stations receives a downlink signal from the base station or from the other relay stations and an uplink signal from the user equipment or from the other relay stations in the current slot, and transmits the received downlink signal to the other relay stations or to the user equipment and the received uplink signal to the other relay stations or to the base station in the next slot;

and

at least one relay station among the plurality of relay stations transmits the downlink signal to the other relay stations or to the user equipment and the uplink signal to the other relay stations or to the base station in the current slot, and receives the downlink signal from the base station or from the other relay stations and the uplink signal from the user equipment or from the other relay stations in the next slot,

wherein the uplink signal and the downlink signal transmitted in the same slot are orthogonal.