Apparatus and method for cancelling interference in a mobile communication system using multiple antennas

• US 20050164658A1
• Filed: 12/01/2004
• Published: 07/28/2005
• Est. Priority Date: 12/02/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Hyuo-Bae, Moon, Yong-Suk, Oh, Hyun-Seok, Lee, Hye-Jeong, Lee, Jeong-Won, Yu, Hyun-Seok, Choi, Gio-Kyu
• Granted Patent: US 7,574,178 B2
• Time in Patent Office: Days
• US Class Current: 455/121
• CPC Class Codes: H04B 7/082 selecting best antenna path
• CPC Class Codes: H04B 7/0822 according to predefined selection scheme
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion

Abstract

An apparatus and method for improving the performance of an error correction code against the effects of error waves in a Multi-Input Multi-Output (MIMO) communication system are provided. In a receiver of the MIMO communication system, a Minimum Mean Square Error (MMSE) receiver unit estimates transmitted signals from at least two paths using signals received at each of receive antennas, a signal deprocessor selects one of the estimated signals, stores the other estimated signal, assigns weighting values to the selected signal and a previous detected signal, combines the weighted signals, and detects transmitted data from the combined signal, a signal reproducer reproduces a transmitted signal from the detected transmitted data, and a subtractor updates the received signals by subtracting the reproduced transmitted signal from the received signals and provides them to the MMSE receiver unit.

Claims

1. A method of receiving a plurality of signals at a plurality of receive antennas in different paths from a plurality of transmit antennas in a mobile communication system, the method comprising the steps of:

(1) estimating a transmitted signal from a predetermined path using signals received at each of the receive antennas using a predetermined rule;

(2) detecting transmitted data from the estimated transmitted signal by predetermined signal deprocessing;

(3) reproducing the transmitted signal from the detected transmitted data by predetermined signal processing;

(4) updating the received signals by subtracting the reproduced transmitted signal from the received signals; and

(5) repeating the steps of (1) through (4) until transmitted data from all paths are detected from the updated received signals.

2. The method of claim 1, wherein different data are transmitted through the transmit antennas in the mobile communication system.

3. The method of claim 1, wherein the step of (1) comprises the step of estimating a signal from a path having the highest Signal to Interference and Noise Ratio (SINR) among the plurality of paths.

4. A method of receiving a plurality of signals at a plurality of receive antennas in different paths from a plurality of transmit antennas in a mobile communication system, the method comprising the steps of:

(1) estimating transmitted signals from at least two predetermined paths using signals received at each of the receive antennas using a predetermined rule;

(2) selecting one of the estimated signals according to a predetermined method and storing the other estimated signal;

(3) assigning weighting values to the selected signal and a previous detected signal and combining the weighted signals;

(4) detecting transmitted data from the combined signal by predetermined signal deprocessing;

(5) reproducing the transmitted signal from the detected transmitted data by predetermined signal processing;

(6) updating the received signals by subtracting the reproduced transmitted signal from the received signals; and

(7) repeating the steps of (1) through (4) until transmitted data from all paths are detected from the updated received signals.

5. The method of claim 4, wherein the step of (3) comprises the step of assigning a first weighting value y to the selected signal and a second weighting value (1−

γ

) to the previous detected signal.

6. The method of claim 4, wherein the step of (1) comprises the step of estimating signals from at least two paths having the highest Signal to Interference and Noise Ratio (SINR) among the plurality of paths.

7. The method of claim 4, wherein the step of (2) comprises the step of selecting a signal from a path having the highest Signal to Interference and Noise Ratio (SINR) among the plurality of paths and buffering a signal from a path having the second to highest SINR to be combined with a transmitted signal selected at a next stage.

8. The method of claim 4, wherein the step of (4) comprises the step of detecting the transmitted data from the selected transmitted signal by the predetermined signal deprocessing in the absence of the previous detected transmitted signal.

9. A method of receiving a plurality of signals at a plurality of receive antennas in different paths from a plurality of transmit antennas in a mobile communication system, the method comprising the steps of:

(1) transmitting different data through the plurality of transmit antennas;

(2) estimating transmitted signals corresponding to at least two transmit antennas using signals received at each of the receive antennas using a predetermined rule, the received signals corresponding to the data transmitted from the plurality of transmit antennas;

(3) selecting one of the estimated signals according to a predetermined method and storing the other estimated signal;

(4) assigning weighting values to the selected signal and a previous detected signal and combining the weighted signals;

(5) detecting transmitted data corresponding to one of the transmit antennas from the combined signal by predetermined signal deprocessing;

(6) reproducing a transmitted signal corresponding to the transmit antenna from the detected transmitted data by predetermined signal processing;

(7) updating the received signals by subtracting the reproduced transmitted signal from the received signals; and

(8) repeating the steps of (2) through (7) until transmitted data from all the transmit antennas are detected from the updated received signals.

10. The method of claim 9, wherein the step of (4) comprises the step of assigning a first weighting value My to the selected signal and a second weighting value (1−

γ

) to the previous detected signal.

11. The method of claim 9, wherein the step of (2) comprises the step of estimating signals from at least two paths having the highest Signal to Interference and Noise Ratio (SINR) among the plurality of paths.

12. The method of claim 9, wherein the step of (3) comprises the step of selecting a signal from a path having the highest Signal to Interference and Noise Ratio (SINR) among the plurality of paths and buffering a signal from a path having the second to highest SINR to be combined with a transmitted signal selected at a next stage.

13. An apparatus for receiving a plurality of signals at a plurality of receive antennas in different paths from a plurality of transmit antennas in a mobile communication system, the apparatus comprising:

a Minimum Mean Square Error (MMSE) receiver unit for estimating transmitted signals from at least two predetermined paths using signals received at each of the receive antennas using a predetermined rule;

a signal deprocessor for selecting one of the estimated signals according to a predetermined method, storing the other estimated signal, assigning weighting values to the selected signal and a previous detected signal, combining the weighted signals, and detecting transmitted data from the combined signal by predetermined signal deprocessing;

a signal reproducer for reproducing a transmitted signal from the detected transmitted data by predetermined signal processing; and

a subtractor for updating the received signals by subtracting the reproduced transmitted signal from the received signals and providing the updated received signals to the MMSE receiver unit.

14. The apparatus of claim 13, wherein the MMSE receiver unit assigns a first weighting value y to the selected signal and a second weighting value (1−

γ

) to the previous detected signal.

15. The apparatus of claim 13, wherein the MMSE receiver unit estimates signals from at least two paths having the highest Signal to Interference and Noise Ratio (SINR) among the plurality of paths.

16. The apparatus of claim 13, wherein the MMSE receiver unit selects a signal from a path having the highest SINR among the plurality of paths and buffering a signal from a path having the second to highest SINR to be combined with a transmitted signal selected at a next stage.

17. The apparatus of claim 13, wherein the MMSE receiver unit detects the transmitted data from the selected transmitted signal by the predetermined signal deprocessing in the absence of the previous detected transmitted signal.