Relay communication system

• US 9,485,006 B2
• Filed: 04/19/2010
• Issued: 11/01/2016
• Est. Priority Date: 04/24/2009
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Awad, Yassin Aden
• Primary Examiner(s): CHOUDHRY, SAMINA F
• Application Number:
  US13/138,741
• Publication Number:
  US 20120015661A1
• Time in Patent Office: 2,388 Days
• Field of Search: 370/315
• US Class Current: 1/1
• 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: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0039 Frequency-contiguous, i.e. with no allocation of frequencies for one user or terminal between the frequencies allocated to another
• CPC Class Codes: H04L 5/0092 Indication of how the channel is divided
• CPC Class Codes: H04W 40/22 using selective relaying for reaching a BTS [Base Transceiver Station] or an access point
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A relay communications system is described in which a base station is able to dynamically vary or semi-statically vary the number of resource blocks used to carry relay control data within a transmitted sub-frame. Default resource blocks are used to include a first part of the control data and if additional control data is provided, then the first part of the control data identifies that there is additional control data and provides information to allow the additional data to be located within the sub-frame.

Claims

1. A relay station operable to relay data received from a remote station to one or more communications devices, the relay station comprising:

a transceiver circuit configured to transmit signals to the remote station and the one or more communications devices and configured to receive signals from the remote station and the one or more communications devices; and

a communications controller configured;

i) to generate a sub-frame comprising an initial part including control data and a subsequent part without data;

ii) to control said transceiver circuit so that the transceiver circuit transmits the control data in the initial part of the sub-frame and then switches to a receive mode to receive part of a sub-frame transmitted by the remote station;

iii) to recover relay control data from the received part of the sub-frame transmitted by the remote station;

iv) to determine from the recovered relay control data if the received part of the sub-frame also includes user data for the relay station and to recover such user data if included,

wherein the relay station is operable to obtain a numeric value representing a quantity of communications resources configured to carry said relay control data, and

wherein said communications controller is operable to use the numeric value to locate and recover the relay control data from the received part of the sub-frame transmitted from the remote station.

2. A relay station according to claim 1, which is synchronized with the remote station so that sub-frames transmitted by the relay station and the remote station begin at a same time and end at a same time.

3. A relay station according to claim 1, operable to obtain the numeric value prior to receiving said received part of the sub-frame.

4. A relay station according to claim 1, operable to receive the numeric value in a predefined portion of the received part of the sub-frame.

5. A relay station according to claim 4, wherein the sub-frame transmitted by the remote station includes at least a first portion of the relay control data on predetermined communications resources, which first portion includes data identifying if further relay control data is included on other communications resources and wherein said communications controller is operable to process the first portion of the relay control data to identify if the sub-frame includes further relay control data and if so, is operable to locate and recover the further relay control data.

6. A relay station according to claim 1, wherein said relay control data is distributed over a number of communication resources and wherein the communications controller is operable to use a predefined equation to identify the resources on which the relay control data is carried.

7. A relay station according to claim 6, wherein the communications controller is operable to use a predefined equation that relates virtual resource blocks to physical resource blocks to identify the communication resources on which the relay control data is carried and uses a cell ID of the remote station to identify a starting virtual resource block.

8. A relay station according to claim 6, wherein the communications controller is operable to use the following equation for an index, RB_index(i), of a resource block on which the relay control data is carried:

RB_index(i)=(N_ID^Cell mod 6+└

i/2┘

*└

N_RB^DL/N_{RB_max}^Alloc┘

+(i mod

     2)*┌

N_RB^DL/2┐

)mod N_RB^DL;

Where;

i=0, 1, to N_{RB_max}^Alloc−

1

N_ID^Cell is the cell ID

N_RB^DL is the downlink system bandwidth in terms of the number of resource blocks (RBs)

N_{RB_max}^Alloc is the total number of RBs that will be allocated for the relay control data

└

┘

is the floor function defining the smallest integer not greater than the expression inside the brackets

┌

┐

is the ceiling function defining the smallest integer not less than the expression inside the brackets.

9. A relay station according to claim 6, wherein one or more default communications resources are defined to carry at least some of the relay control data and wherein the default communications resources used depends on an identity of the remote station that transmitted the sub-frame.

10. A relay station according to claim 1, wherein the communications resources include time domain resources and frequency domain resources.

11. A method performed by a relay station operable to relay data received from a remote station to one or more communications devices, the method comprising:

using a communications controller to;

i) generate a sub-frame comprising an initial part including control data and a subsequent part without data;

ii) control a transceiver circuit so that the transceiver circuit transmits the control data in the initial part of the sub-frame and then switches to a receive mode to receive part of a sub-frame transmitted by the remote station;

iii) recover relay control data from the received part of the sub-frame transmitted by the remote station;

iv) determine from the recovered relay control data if the received part of the sub-frame also includes user data for the relay station and to recover such user data if included,

wherein the method further comprises obtaining a numeric value representing a quantity of communications resources configured to carry said relay control data, and

wherein said communications controller uses the numeric value to locate and recover the relay control data from the received part of the sub-frame transmitted from the remote station.

12. A non-transitory media including a computer program product comprising computer implementable instructions for causing a programmable computer device to become configured as a relay station operable to relay data received from a remote station to one or more communications devices, the relay station comprising:

a transceiver circuit configured to transmit signals to the remote station and the one or more communications devices and configured to receive signals from the remote station and the one or more communications devices; and

a communications controller operable;

i) to generate a sub-frame comprising an initial part including control data and a subsequent part without data;

ii) to control said transceiver circuit so that the transceiver circuit transmits the control data in the initial part of the sub-frame and then switches to a receive mode to receive part of a sub-frame transmitted by the remote station;

iii) to recover relay control data from the received part of the sub-frame transmitted by the remote station;

iv) to determine from the recovered relay control data if the received part of the sub-frame also includes user data for the relay station and to recover such user data if included,

wherein the relay station is operable to obtain a numeric value representing a quantity of communications resources configured to carry said relay control data, and

wherein said communications controller is operable to use the numeric value to locate and recover the relay control data from the received part of the sub-frame transmitted from the remote station.

13. A relay station operable to relay data received from a remote station to one or more communications devices, the relay station comprising:

a transceiver circuit configured to transmit signals to the remote station and the one or more communications devices and configured to receive signals from the remote station and the one or more communications devices;

a communications controller operable;

i) to generate a sub-frame comprising an initial part including control data and a subsequent part without data;

ii) to control said transceiver circuit so that the transceiver circuit transmits the control data in the initial part of the sub-frame and then switches to a receive mode to receive part of a sub-frame transmitted by the remote station;

iii) to recover relay control data from the received part of the sub-frame transmitted by the remote station;

iv) to determine from the recovered relay control data if the received part of the sub-frame also includes user data for the relay station and to recover such user data if included,

wherein the relay station is operable to receive data identifying a number of communications resources used to carry said relay control data and wherein said communications controller is operable to use the received data identifying the number of communications resources to locate and recover the relay control data from the received part of the sub-frame transmitted from the remote station,

wherein said relay control data is distributed over a number of communication resources and wherein the communications controller is operable to use a predefined equation to identify the resources on which the relay control data is carried, and

wherein the communications controller is operable to use the following equation for an index, RB_index(i), of a resource block on which the relay control data is carried;

RB_index(i)=(N_ID^Cell mod 6+└

i/2┘

*└

N_RB^DL/N_{RB_max}^Alloc┘

+(i mod

     2)*┌

N_RB^DL/2┐

)mod N_RB^DL;

Where;

i=0, 1, to N_{RB_max}^Alloc−

1

N_ID^Cell is the cell ID

N_RB^DL is the downlink system bandwidth in terms of the number of resource blocks (RBs)

N_{RB_max}^Alloc is the total number of RBs that will be allocated for the relay control data

└

┘

is the floor function defining the smallest integer not greater than the expression inside the brackets

┌

┐

is the ceiling function defining the smallest integer not less than the expression inside the brackets.

14. A method performed by a relay station operable to relay data received from a remote station to one or more communications devices, the method comprising:

using a communications controller to;

i) generate a sub-frame comprising an initial part including control data and a subsequent part without data;

ii) control a transceiver circuit so that the transceiver circuit transmits the control data in the initial part of the sub-frame and then switches to a receive mode to receive part of a sub-frame transmitted by the remote station;

iii) recover relay control data from the received part of the sub-frame transmitted by the remote station;

iv) determine from the recovered relay control data if the received part of the sub-frame also includes user data for the relay station and to recover such user data if included,

wherein the method further comprises receiving data from the remote station identifying a number of communications resources used to carry said relay control data and wherein the communications controller uses the received data identifying the number of communications resources to locate and recover the relay control data from the received part of the sub-frame transmitted from the remote station,

wherein said relay control data is distributed over a number of communication resources and wherein the communications controller uses a predefined equation to identify the resources on which the relay control data is carried, and

wherein the communications controller uses the following equation for an index, RB_index(i), of a resource block on which the relay control data is carried;

RB_index(i)=(N_ID^Cell mod 6+└

i/2┘

*└

N_RB^DL/N_{RB_max}^Alloc┘

+(i mod

     2)*┌

N_RB^DL/2┐

)mod N_RB^DL;

Where;

i=0, 1, to N_{RB_max}^Alloc−

1

N_ID^Cell is the cell ID

N_RB^DL is the downlink system bandwidth in terms of the number of resource blocks (RBs)

N_{RB_max}^Alloc is the total number of RBs that will be allocated for the relay control data

└

┘

is the floor function defining the smallest integer not greater than the expression inside the brackets

┌

┐

is the ceiling function defining the smallest integer not less than the expression inside the brackets.

15. A method performed by a communications station, the method comprising:

generating a sub-frame comprising an initial part including control data and a subsequent part including user data for devices served by the communications station;

specifying communications resources to use to carry the control data and the user data of the sub-frame; and

transmitting the control data and the user data of the generated sub-frame for receipt by the devices served by communications station,

wherein the generating includes relay control data, for one or more relay stations served by the communications station, within the subsequent part of the sub-frame,

wherein the method further comprises varying the number of communications resources used to carry the relay control data in the subsequent part of the sub-frame and transmitting data to the one or more relay stations identifying the number of communications resources used to carry the relay control data, and

wherein said relay control data is distributed over a number of communication resources and wherein said specifying uses a predefined equation to specify the resources on which the relay control data is carried, and

wherein the specifying uses the following equation for specifying an index, RB_index(i), of a resource block on which the relay control data is to be carried;

RB_index(i)=(N_ID^Cell mod 6+└

i/2┘

*└

N_RB^DL/N_{RB_max}^Alloc┘

+(i mod

     2)*┌

N_RB^DL/2┐

)mod N_RB^DL;

Where;

i=0, 1, to N_{RB_max}^Alloc−

1

N_ID^Cell is the cell ID

N_RB^DL is the downlink system bandwidth in terms of the number of resource blocks (RBs)

N_{RB_max}^Alloc is the total number of RBs that will be allocated for the relay control data

└

┘

is the floor function defining the smallest integer not greater than the expression inside the brackets

┌

┐

is the ceiling function defining the smallest integer not less than the expression inside the brackets.

16. A relay station operable to relay data received from a remote station to one or more communications devices, the relay station comprising:

a transceiver circuit configured to transmit signals to the remote station and the one or more communications devices and further configured to receive signals from the remote station and the one or more communications devices; and

a communications controller configured;

i) to generate a sub-frame comprising an initial part including control data and a subsequent part without data;

ii) to control said transceiver circuit so that the transceiver circuit transmits the control data in the initial part of the sub-frame and then switches to a receive mode to receive part of a sub-frame transmitted by the remote station;

iii) to recover relay control data from the received part of the sub-frame transmitted by the remote station; and

iv) to determine from the recovered relay control data if the received part of the sub-frame also includes user data for the relay station and to recover such user data if included,

wherein the relay station is operable to obtain a numeric value representing a quantity of communications resources configured to carry said relay control data, and

wherein said communications controller is operable to use the numeric value to locate and recover the relay control data from the received part of the sub-frame transmitted from the remote station based on an equation that relates at least one virtual resource block configured to carry said relay control data to said numeric value.

17. A method performed by a relay station operable to relay data received from a remote station to one or more communications devices, the method comprising:

using a communications controller to;

i) generate a sub-frame comprising an initial part including control data and a subsequent part without data;

ii) control a transceiver circuit so that the transceiver circuit transmits the control data in the initial part of the sub-frame and then switches to a receive mode to receive part of a sub-frame transmitted by the remote station;

iii) recover relay control data from the received part of the sub-frame transmitted by the remote station; and

iv) determine from the recovered relay control data if the received part of the sub-frame also includes user data for the relay station and to recover such user data if included,

wherein the method further comprises a numeric value representing a quantity of communications resources configured to carry said relay control data, and

wherein said communications controller uses the numeric value to locate and recover the relay control data from the received part of the sub-frame transmitted from the remote station based on an equation that relates at least one virtual resource block configured to carry said relay control data to said numeric value.