Self-interference cancellation method and apparatus of relay using the same frequency band in OFDM-based radio communication system

• US 8,725,067 B2
• Filed: 08/14/2009
• Issued: 05/13/2014
• Est. Priority Date: 08/14/2008
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Ahn, Jae Young, Ko, Young Jo, Lee, Heesoo
• Primary Examiner(s): GESESSE, TILAHUN
• Application Number:
  US13/059,002
• Publication Number:
  US 20110143655A1
• Time in Patent Office: 1,733 Days
• Field of Search: 455/7, 455/9, 455/16.15
• US Class Current: 455/11.1
• 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 estimating a radio channel between a transmit antenna of a relay and a receive antenna of the relay;

an estimated self-interference generator generating an estimated self-interference based on an estimated radio channel; and

a self-interference cancellation unit canceling the estimated self-interference in a received signal received via the receive antenna,

wherein the relay transmits data and comprises;

a reference signal generator configured to generate self-interference cancellation reference signal and an uplink reference signal, generating the 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, for the base station to perform a coherent demodulation, and

a transmitter to transmit the self-interference cancellation reference signal, the data, and the uplink reference signal to a base station accessing the relay, and

wherein the channel estimator receives the self-interference cancellation reference signal and estimates a radio channel based on the received self-interference cancellation reference signal.

2. The apparatus of claim 1, wherein the relay transmits data using a plurality of frequency bands, and comprises:

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 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 1, 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.

4. The apparatus of claim 1, wherein the self-interference cancellation reference signal sequence and the uplink reference signal sequence are orthogonal to each other.

5. 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 generating a self-interference cancellation reference signal, 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;

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

a receiver receiving 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 estimating 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 generating an estimated self-interference based on an estimated radio channel of the first frequency band; and

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

6. The apparatus of claim 5, 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.

7. The apparatus of claim 5, 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.

8. The apparatus of claim 7, wherein the self-interference cancellation reference signal sequence and the uplink reference signal sequence are orthogonal to each other.