Method and apparatus for interference cancellation for antenna arrays

• US 9,124,475 B2
• Filed: 10/11/2011
• Issued: 09/01/2015
• Est. Priority Date: 09/19/2011
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Li, Li Erran, Marzetta, Thomas
• Primary Examiner(s): Acolatse, Kodzovi
• Application Number:
  US13/270,747
• Publication Number:
  US 20130089009A1
• Time in Patent Office: 1,421 Days
• Field of Search: 370/278, 370/282
• US Class Current: 1/1
• CPC Class Codes: H04B 7/14 Relay systems
• CPC Class Codes: H04L 25/03305 Joint sequence estimation and interference removal joint detection of several desired signals H04L25/03331
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 5/16 Half-duplex systems; Simplex/duplex switching; Transmission of break signals non-automatically inverting the direction of transmission

Abstract

Embodiments of the claimed subject matter provide methods and apparatuses for interference cancellation. One embodiment of a method includes estimating, for an antenna in an antenna array including a plurality of antennas, interference parameters using analog signals received at the antenna on each of a plurality of subcarriers. Each interference parameter is associated with one of a plurality of symbols transmitted to one of a plurality of users on one of the plurality of subcarriers. This embodiment also includes canceling interference from analog signals received by the antenna on the plurality of subcarriers using the estimated interference parameters.

Claims

1. A method, comprising:

estimating, for an antenna in an antenna array comprising a plurality of antennas, interference parameters using digital signals generated based on first analog baseband signals, wherein the first analog baseband signals are generated using first analog radiofrequency signals, wherein the first analog radiofrequency signals are received at the antenna on each of a plurality of subcarriers, and wherein each interference parameter is associated with one of a plurality of digital symbols;

modifying the plurality of digital symbols using the estimated interference parameters;

encoding the plurality of modified digital symbols;

converting the plurality of modified digital symbols to second analog baseband signals;

converting the second analog baseband signals to second analog radiofrequency signals;

canceling interference from the first analog radiofrequency signals received by the antenna on the plurality of subcarriers using the second analog radiofrequency signals;

converting, the first analog radiofrequency signals to the first analog baseband signals after canceling interference from the first radiofrequency signals, and

scheduling subsets of a plurality of users for reception or transmission in half-duplex mode based locations of the plurality of users and angle-of-arrival of signals from the plurality of users.

2. The method of claim 1, wherein the number of interference parameters for the antenna is independent of the number of other antennas in the antenna array.

3. The method of claim 1, wherein estimating the interference parameters comprises estimating the interference parameters to minimize differences between the first analog radiofrequency signals received at the antenna and products of the interference parameters and the plurality of digital symbols.

4. The method of claim 1, comprising converting the first analog baseband signals to the digital signals after canceling the interference from the first analog radiofrequency signals.

5. The method of claim 1, comprising pre-coding the plurality of digital symbols for transmission over an air interface concurrently with canceling interference from the first analog radiofrequency signals received by the antenna on a plurality of subcarriers.

6. The method of claim 5, comprising transmitting the plurality of digital symbols in full-duplex mode and concurrently receiving uplink signals from a plurality of users transmitting in full-duplex mode.

7. The method of claim 5, comprising converting the plurality of digital symbols to a corresponding plurality of analog signals transmitting the corresponding plurality of analog signals in full-duplex mode and concurrently receiving uplink signals from the subsets of users transmitting in the half-duplex mode.

8. The method of claim 7, wherein scheduling the subsets of the plurality of users for reception or transmission in the half-duplex mode comprises scheduling the subsets of the plurality of users for reception or transmission in the half-duplex mode based on an estimate of inter-user interference.

9. The method of claim 7, comprising estimating interference parameters for each antenna in the antenna array and canceling interference from analog signals received by the plurality of antennas in the antenna array using the estimated interference parameters.

10. A transceiver configured to be communicatively coupled to an antenna in an antenna array comprising a plurality of antennas, wherein the transceiver comprises:

a software logic configured to estimate interference parameters using digital signals generated based on first analog baseband signals, wherein the first analog baseband signals are generated using first analog radiofrequency signals, wherein the first analog radiofrequency signals are received at the antenna on each of a plurality of subcarriers, and wherein each interference parameter is associated with one of a plurality of digital symbols,

an encoder configured to modify the plurality of digital symbols using the estimated interference parameters and encode the plurality of modified digital symbols;

a digital-to-analog converter to convert the plurality of modified digital symbols to second analog baseband signals;

circuitry configured to convert the second analog baseband signals to second analog radiofrequency signals;

circuitry configured to cancel interference from the first analog radiofrequency signals received by the antenna on the plurality of subcarriers using the second analog radiofrequency signals;

circuitry configured to convert the first analog radiofrequency signals to the first analog baseband signals after canceling interference from the first radiofrequency signals, and

circuitry configured to schedule subsets of a plurality of users for reception or transmission in half-duplex mode based locations of the plurality of users and angle-of-arrival of signals from the plurality of users.

11. The transceiver of claim 10, wherein the number of interference parameters for the antenna is independent of the number of other antennas in the antenna array.

12. The transceiver of claim 10, wherein the software logic is configured to estimate the interference parameters to minimize differences between the first analog radiofrequency signals received at the antenna and products of the interference parameters and the plurality of digital symbols.

13. The transceiver of claim 10, comprising receive circuitry configured to convert the first analog baseband signals to the digital signals after canceling the interference from the first analog radiofrequency signals.

14. The transceiver of claim 13, wherein the receive circuitry is configured to provide feedback based upon the digital signals to the software logic, and wherein the software logic is configured to estimate the interference parameters based upon the feedback.

15. The transceiver of claim 13, comprising transmit circuitry configured to pre-code the plurality of digital symbols for transmission over an air interface concurrently with the software logic canceling interference from the first analog radiofrequency signals received by the antenna on a plurality of subcarriers.

16. The transceiver of claim 15, wherein the transmit circuitry is configured to transmit the plurality of digital symbols in full-duplex mode and wherein the receive circuitry is configured to concurrently receive uplink signals from a plurality of users transmitting in full-duplex mode.

17. The transceiver of claim 15, wherein the transmit circuitry is configured to transmit the plurality of digital symbols in full-duplex mode and wherein the receive circuitry is configured to concurrently receive uplink signals from subsets of the plurality of users transmitting in the half-duplex mode.

18. The transceiver of claim 17, wherein the transceiver is configured to schedule the subsets of users for reception or transmission in half-duplex mode based on estimates of inter-user interference.

19. A system comprising:

a plurality of transceivers, wherein each of the plurality of transceivers is configured to be communicatively coupled to one of a plurality of antennas in an antenna array, and wherein each transceiver comprises;

a software logic configured to estimate interference parameters using digital signals generated based on first analog baseband signals, wherein the first analog baseband signals are generated using first analog radiofrequency signals, wherein the first analog radiofrequency signals are received at the antenna on each of a plurality of subcarriers, and wherein each interference parameter is associated with one of a plurality of digital symbols,

an encoder configured to modify the plurality of digital symbols using the estimated interference parameters and encode the plurality of modified digital symbols;

a digital-to-analog converter to convert the plurality of modified digital symbols to second analog baseband signals;

circuitry configured to convert the second analog baseband signals to second analog radiofrequency signals;

circuitry configured to cancel interference from the first analog radiofrequency signals received by the antenna on the plurality of subcarriers using the second analog radiofrequency signals;

circuitry configured to convert the first analog radiofrequency signals to the first analog baseband signals after canceling interference from the first radiofrequency signals, and

circuitry configured to schedule subsets of a plurality of users for reception or transmission in half-duplex mode based locations of the plurality of users and angle-of-arrival of signals from the plurality of users.