Data throughput for cell-edge users in a LTE network using down-link repeaters and up link HARQ relays
View Patent ↗A combination of repeaters and relays is used to improve the data throughput for user equipment (“UE”) near the cell edge in a LTE network. Amplify-and-forward repeaters and decode-and-forward relays enhance the down-link and up-link, respectively. Relay assistance on the up-link occurs when the evolved Node B (“eNB”) requests a retransmission (HARQ) from the UE at which point the UE and relay transmit simultaneously in a cooperative fashion. The quality of the up-link signal received by the eNB is improved due to a favorable channel through the relay. An analysis shows that relay assistance improves the throughput for a cell-edge user when the average delay per data transport block is allowed to increase.
1. A wireless communication system, comprising:
a base station configured for communication within a cell;
an up-link relay;
a down-link repeater co-located with the up-link relay;
a donor antenna coupled to the output of the up-link relay and further coupled to the input of the down-link repeater; and,
a service antenna coupled to the input of the up-link relay and further coupled to the output of the down-link repeater,
wherein the up-link relay only receives up-link signals, decodes the received up-link signals, recodes the decoded up-link signals, and transmits the recoded up-link signals, and
wherein the down-link repeater only receives down-link signals, amplifies the received down-link signals, and re-transmits the amplified down-link signals.
2. The wireless communication system of claim 1 , further comprising user equipment located within the cell, wherein the user equipment is configured for transmitting and receiving signals.
3. The wireless communication system of claim 1 , wherein the wireless communication system employs automatic repeat requests in response to errors detected in received signals, wherein the base station further comprises a scheduler configured for controlling resource allocation for the up-link and the down-link signals.
4. The wireless communication system of claim 3 , wherein:
the user equipment is configured for transmitting control signals to the base station via an up-link control channel during a repeat request retransmission period; and,
the up-link relay is configured for transmitting data signals to the base station via an up-link shared channel during the repeat request retransmission period.
5. The wireless communication system of claim 4 , wherein the up-link relay is configured for determining whether to re-transmit the up-link signals based on an operating protocol of the user equipment.
6. The wireless communication system of claim 3 , wherein:
the user equipment is configured for transmitting control signals to the base station via an up-link control channel during a repeat request transmission period;
the user equipment is further configured for transmitting data signals to the base station via an up-link shared channel overlapping with the transmission of the control signals during the repeat request retransmission period; and,
the up-link relay is configured for transmitting the data signals to the base station via the up-link shared channel during the repeat request retransmission.
7. The wireless communication system of claim 3 , wherein the base station is further configured for scheduling and resource allocation for the up-link signals within the wireless communication system.
8. The wireless communication system of claim 3 , wherein the up-link relay emulates a second user equipment to extract timing advance information.
9. The wireless communication system of claim 3 , wherein the up-link relay emulates a second user equipment periodically to maintain power control and receive timing advance updates.
10. The wireless communication system of claim 3 , wherein the user equipment is further configured for transmitting control information directly to the base station when the up-link relay is transmitting.
11. A method for wireless communication in a network, the network having a base station, user equipment, and a co-located up-link relay and down-link repeater, comprising:
transmitting down-link signals from a base station;
receiving the down-link signals transmitted from the base station by a down-link repeater via a donor antenna;
transmitting the down-link signals from the repeater via a service antenna;
receiving the down-link signals by the user equipment;
transmitting up-link signals by the user equipment;
receiving the up-link signals transmitted from the user equipment by an up-link relay via the service antenna;
transmitting the up-link signals from the up-link relay via the donor antenna; and,
receiving the up-link signals by the base station,
wherein the up-link relay only receives up-link signals, decodes the received up-link signals, recodes the decoded up-link signals, and transmits the recoded up-link signals, and
wherein the down-link repeater only receives down-link signals, amplifies the received down-link signals, and re-transmits the amplified down-link signals.
12. The method for wireless communication in a network, the network having a base station, user equipment, and a co-located up-link relay and down-link repeater as set out in claim 11 , further comprising:
transmitting a repeat request from the base station to the user equipment and the up-link relay;
transmitting up-link control signals from the user equipment to the base station during a retransmission period;
transmitting up-link data signals from the up-link relay during the retransmission period; and,
receiving the up-link control and data signals by the base station.
13. The method for wireless communication in a network, the network having a base station, user equipment, and a co-located up-link relay and down-link repeater as set out in claim 12 , further comprising performing an incremental redundancy function of the up-link data signals.
14. The method for wireless communication in a network, the network having a base station, user equipment, and a co-located up-link relay and down-link repeater as set out in claim 12 , further comprising:
determining whether to transmit up-link signals from the up-link relay based on the operating protocol of the user equipment.
15. The method for wireless communication in a network, the network having a base station, user equipment, and a co-located up-link relay and down-link repeater as set out in claim 11 , further comprising:
transmitting a repeat request from the base station to the user equipment and the up-link relay;
transmitting up-link control and data signals from the user equipment to the base station during a retransmission period;
transmitting up-link data signals from the up-link relay to the base station during the retransmission period;
receiving the up-link control and data signals from the user equipment by the base station;
receiving the up-link data signals from the up-link relay by the base station; and,
performing an incremental redundancy function of the up-link data signals from the user equipment and the up-link data signals from the up-link relay.
16. A method for wireless communication in a network, the network having a base station, user equipment, and a co-located up-link relay and down-link repeater, comprising:
transmitting down-link signals from a base station;
receiving the down-link signals by a down-link repeater via a donor antenna; amplifying the down-link signals by a down-link repeater;
transmitting the amplified down-linked signals to a user equipment via a service antenna;
receiving the amplified down-link signals by the user equipment;
transmitting up-link signals from the user equipment;
receiving the up-link signals transmitted by the user equipment by an up-link relay via the service antenna;
decoding the up-link signals;
re-encoding the decoded up-link signals;
transmitting the re-encoded up-link, signals to a base station via the donor antenna; and,
receiving the up-link signals by the base station,
wherein the up-link relay only receives up-link signals, decodes the received up-link signals, recodes the decoded up-link signals, and transmits the recoded up-link signals, and
wherein the down-link repeater only receives down-link signals, amplifies the received down-link signals, and re-transmits the amplified down-link signals.
17. The method for wireless communication in a network, the network having a base station, user equipment, and a co-located up-link relay and down-link repeater as set out in claim 16 , further comprising:
transmitting an automatic repeat request from the base station to the user equipment and the up-link relay;
transmitting up-link control signals via an up-link control channel from the user equipment to the base station during a retransmission period;
transmitting up-link data signals via an up-link shared channel from the up-link relay during the retransmission period; and,
receiving the up-link control and data signals by the base station.
18. The method for wireless communication in a network, the network having a base station, user equipment, and a co-located up-link relay and down-link repeater as set out in claim 17 , further comprising:
determining whether to transmit the up-link control signals based on the operating protocol of the user equipment.
19. The method for wireless communication in a network, the network having a base station, user equipment, and a co-located up-link relay and down-link repeater as set out in claim 16 , further comprising:
transmitting a repeat request from the base station to the user equipment and the up-link relay;
transmitting control signals to the base station from the user equipment via an up-link control channel during a repeat request transmission period;
transmitting data signals to the base station from the user equipment via an up-link shared channel overlapping with the transmission of the control signals during the repeat request retransmission period;
transmitting up-link data signal from the up-link relay via the up-link shared channel to the base station during the retransmission period;
receiving the up-link control and data signals from the user equipment by the base station;
receiving the up-link data signals from the up-link relay by the base station; and,
performing an incremental redundancy function of the up-link data signals from the user equipment and the up-link data signals from the up-link relay.