SELF-INTERFERENCE CANCELLATION METHOD AND APPARATUS OF RELAY USING THE SAME FREQUENCY BAND IN OFDM-BASED RADIO COMMUNICATION SYSTEM

• US 20110143655A1
• Filed: 08/14/2009
• Published: 06/16/2011
• Est. Priority Date: 08/14/2008
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Ahn, Jae Young, Ko, Young Jo, Lee, Heesoo
• Granted Patent: US 8,725,067 B2
• Time in Patent Office: Days
• US Class Current: 455/9
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• 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 7/15585 by interference cancellation
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

Provided is a self-interference cancellation method and apparatus that may remove self-interference occurring when a transmission signal of a transmit antenna is received, directly or via a reflector, by a receive antenna in a relay using the same frequency band in an orthogonal frequency division multiplexing (OFDM)-based radio communication system.

Claims

1. A self-interference cancellation apparatus comprising:

a channel estimator to estimate a radio channel between a transmit antenna of a relay and a receive antenna of the relay;

an estimated self-interference generator to generate an estimated self-interference based on the estimated radio channel; and

a self-interference cancellation unit to cancel the estimated self-interference in a received signal received via the receive antenna.

2. The apparatus of claim 1, wherein:

the relay transmits data using a plurality of frequency bands, and comprises;

a reference signal generator to generate a self-interference cancellation reference signal; and

a transmitter to transmit the self-interference cancellation reference signal using the transmit antenna and a first frequency band included in the plurality of frequency bands, and

the channel estimator receives the self-interference cancellation reference signal using the receive antenna, and estimates a radio channel of a second frequency band among the plurality of frequency bands based on the received self-interference cancellation reference signal.

3. The apparatus of claim 2, wherein:

the reference signal generator generates an uplink reference signal using an uplink reference signal sequence that is selected from a reference signal sequence group including a plurality of reference signal sequences,

the transmitter transmits the data and the uplink reference signal to a base station accessing the relay, and

the uplink reference signal is used for the base station to perform a coherent demodulation for the data.

4. The apparatus of claim 3, wherein the reference signal generator selects a self-interference cancellation reference signal sequence from reference signal sequences excluding the uplink reference signal sequence, and generates the self-interference cancellation reference signal using the self-interference cancellation reference signal sequence.

5. The apparatus of claim 3, wherein the self-interference cancellation reference signal sequence and the uplink reference signal sequence are orthogonal to each other.

6. A relay comprising:

a receiver to receive, from a base station in a first time slot, information associated with a first radio resource group including at least one uplink radio resource; and

a transmitter to transmit first data to the base station in a second time slot followed by the first time slot, using a first uplink radio resource included in the first radio resource group,

wherein the receiver receives second data from a terminal using a second uplink radio resource excluded from the first radio resource group, in the second time slot.

7. The relay of claim 6, wherein the first uplink radio resource or the second uplink radio resource includes at least one frequency band allocated to the relay.

8. The relay of claim 6, wherein the receiver receives information associated with a second radio resource group that includes the first radio resource group, in a third time slot prior to the first time slot.

9. A self-interference cancellation apparatus transmitting first data to a base station using a plurality of frequency bands, the apparatus comprising:

a reference signal generator to generate a self-interference cancellation reference signal;

a transmitter to transmit the self-interference cancellation reference signal using a transmit antenna and a first frequency band among the plurality of frequency bands;

a receiver to receive the self-interference cancellation reference signal using a receive antenna, to receive second data from the base station, and to generate a received signal;

a channel estimator to estimate a channel of the first frequency band between the transmit antenna and the receive antenna, based on the self-interference cancellation reference signal;

an estimated self-interference generator to generate an estimated self-interference based on the estimated channel of the first frequency band; and

a self-interference cancellation unit to cancel the estimated self-interference in the received signal.

10. The apparatus of claim 9, further comprising:

a decoder,

wherein the channel estimator estimates a channel of a second frequency band among the plurality of frequency bands based on the self-interference cancellation reference signal, and

the decoder decodes the second data using the estimated channel of the second frequency band.

11. The apparatus of claim 9, wherein:

the reference signal generator generates an uplink reference signal using an uplink reference signal sequence that is selected from a reference signal sequence group including a plurality of reference signal sequences,

the transmitter transmits the uplink reference signal and the first data to the base station, and

the uplink reference signal is used to perform a coherent demodulation for the first data.

12. The apparatus of claim 11, wherein the reference signal generator selects a self-interference cancellation reference signal sequence from reference signal sequences excluding the uplink reference signal sequence, and generates the self-interference cancellation reference signal using the self-interference cancellation reference signal sequence.

13. The apparatus of claim 12, wherein the self-interference cancellation reference signal sequence and the uplink reference signal sequence are orthogonal to each other.