Systems and Methods for Full-Duplex Signal Shaping

• US 20130215805A1
• Filed: 02/07/2013
• Published: 08/22/2013
• Est. Priority Date: 02/08/2012
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Inventors: Katti, Sachin, Hong, Steven, Mehlman, Jeff
• Granted Patent: US 9,325,432 B2
• Time in Patent Office: Days
• US Class Current: 370/281
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 1/56 with provision for simultaneous communication in two directions
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 5/1423 for simultaneous baseband signals
• CPC Class Codes: H04L 5/143 for modulated signals H04L5/1469 takes precedence

Abstract

The current subject matter relates to a system and a method for processing signals. The system can include a transmitting antenna for transmitting a signal over a plurality of wireless spectrum fragments, a receiving antenna for receiving a signal from the plurality of wireless spectrum fragments, and a signal processing layer in communication with the transmitting and receiving antennas for simultaneously causing reception of the received signal and transmission of the transmitted signal. The signal processing layer can include an interference cancellation component for removing a first portion of interference from the received signal and a filtering component for removing a second portion of the interference from the received signal.

Claims

1. A system for processing signals, comprising a transmitting antenna for transmitting a signal over a plurality of wireless spectrum fragments;

a receiving antenna for receiving a signal from the plurality of wireless spectrum fragments; and

a signal processing layer in communication with the transmitting and receiving antennas for simultaneously causing reception of the received signal and transmission of the transmitted signal, the signal processing layer including

an interference cancellation component for removing a first portion of interference from the received signal, wherein the interference being caused by the transmitted signal and affecting the received signal; and

a filtering component for removing a second portion of the interference from the received signal.

2. The system according to claim 1, wherein the portion of interference to be removed by the interference cancellation component equals to a predetermined amount of power to be removed from the received signal.

3. The system according to claim 2, wherein the predetermined amount of power is determined based on at least one of the following:

dynamic range of at least one of the received and transmitted signals, and a range of expected signal strength;

the dynamic range of the received signal is determined based on a ratio of powers of a strongest received signal and a weakest received signal;

the dynamic range of the transmitted signal is determined based on a ratio of powers of a strongest transmitted signal and a weakest transmitted signal;

the range of expected signal strength is determined based on a distance separating the transmitting antenna and a receiving antenna.

4. The system according to claim 3, wherein the interference cancellation component includes a balanced-unbalanced transformer component for subtracting the predetermined amount of power from the received signal.

5. The system according to claim 1, wherein the interference cancellation component includes at least one passive electronic component.

6. The system according to claim 1, wherein the filtering component includes a receiver circuitry for performing at least one of the following operations

sampling of the received signal;

down-converting the sampled received signal into a narrowband stream; and

filtering the down-converted signal to remove the second portion of the interference.

7. The system according to claim 1, wherein the filtering component includes a transmitter circuitry for performing at least one of the following operations

up-converting of the transmitted signal;

and

filtering the up-converted signal to prevent aliasing of the transmitted signal with at least another signal.

8. The system according to claim 1, wherein the filtering component includes a plurality of filters arranged in a sequence for performing sampling and filtering of the received signal processed by the interference cancellation component to remove the second portion of the interference.

9. The system according to claim 8, wherein the plurality of filters include at least one programmable filter, which includes at least one of the following:

a finite impulse response filter, an infinite impulse response filter, and a resampling filter.

10. The system according to claim 1, wherein the filtering component performs mapping of at least one signal received from at least one communication protocol layer to at least one frequency fragment in a wireless frequency band for transmission by the transmitting antenna.

11. The system according to claim 1, wherein the received signal and the transmitted signal are in the wireless frequency band.

12. A method for processing of signals using a system having a transmitting antenna for transmitting a signal over a plurality of wireless spectrum fragments, a receiving antenna for receiving a signal from the plurality of wireless spectrum fragments, and a signal processing layer in communication with the transmitting and receiving antennas for simultaneously causing reception of the received signal and transmission of the transmitted signal, the method comprising:

removing, using an interference cancellation component of the signal processing layer, a first portion of interference from the received signal, wherein the interference being caused by the transmitted signal and affecting the received signal; and

removing, using a filtering component of the signal processing layer, a second portion of the interference from the received signal.

13. The method according to claim 12, wherein the portion of interference to be removed by the interference cancellation component equals to a predetermined amount of power to be removed from the received signal.

14. The method according to claim 13, wherein the predetermined amount of power is determined based on at least one of the following:

dynamic range of at least one of the received and transmitted signals, and a range of expected signal strength;

the dynamic range of the received signal is determined based on a ratio of powers of a strongest received signal and a weakest received signal;

the dynamic range of the transmitted signal is determined based on a ratio of powers of a strongest transmitted signal and a weakest transmitted signal;

the range of expected signal strength is determined based on a distance separating the transmitting antenna and a receiving antenna.

15. The method according to claim 14, wherein the interference cancellation component includes a balanced-unbalanced transformer component for subtracting the predetermined amount of power from the received signal.

16. The method according to claim 12, wherein the interference cancellation component includes at least one passive electronic component.

17. The method according to claim 12, wherein the filtering component includes a receiver circuitry for performing at least one of the following operations sampling of the received signal;

down-converting the sampled received signal into a narrowband stream; and

filtering the down-converted signal to remove the second portion of the interference.

18. The method according to claim 12, wherein the filtering component includes a transmitter circuitry for performing at least one of the following operations

up-converting of the transmitted signal;

and

filtering the up-converted signal to prevent aliasing of the transmitted signal with at least another signal.

19. The method according to claim 12, wherein the filtering component includes a plurality of filters arranged in a sequence for performing sampling and filtering of the received signal processed by the interference cancellation component to remove the second portion of the interference.

20. The method according to claim 19, wherein the plurality of filters include at least one programmable filter, which includes at least one of the following:

a finite impulse response filter, an infinite impulse response filter, and a resampling filter.

21. The method according to claim 12, wherein the filtering component performs mapping of at least one signal received from at least one communication protocol layer to at least one frequency fragment in a wireless frequency band for transmission by the transmitting antenna.

22. The method according to claim 12, wherein the received signal and the transmitted signal are in the wireless frequency band.