Full duplex radio

• US 10,097,233 B2
• Filed: 08/14/2015
• Issued: 10/09/2018
• Est. Priority Date: 10/22/2014
• Status: Active Grant

• Current Assignee: Analog Devices International Unlimited Company (Analog Devices, Inc.)
• Original Assignee: Analog Devices Global Unlimited Company (Analog Devices, Inc.)
• Inventors: Pratt, Patrick
• Primary Examiner(s): JAIN, RAJ K
• Application Number:
  US14/826,316
• Publication Number:
  US 20160119019A1
• Time in Patent Office: 1,152 Days
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04L 25/00 Baseband systems
• CPC Class Codes: H04L 5/1461 Suppression of signals in the return path, i.e. bidirectional control circuits
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]

Abstract

Embodiments of full duplex radios are disclosed herein. For example, a radio may include: a first transmitter, a second transmitter, and a receiver. The first transmitter may be configured to receive an input signal, process the input signal to generate a first transmit signal, and transmit the first transmit signal. The second transmitter may be configured to receive the input signal, process the input signal to generate a second transmit signal, and couple the second transmit signal into an input path of the receiver. Leakage at the receiver may thus be reduced. Some embodiments of a radio may also include a base band correction circuit and means for reducing transmitter noise that leaks into the receiver.

Claims

1. A full duplex radio with reduced noise, comprising:

a first transmitter;

a second transmitter, different from the first transmitter;

a receiver; and

a noise correction circuit;

wherein;

the first transmitter is to receive an input signal, process the input signal to generate a first transmit signal, and transmit the first transmit signal,

the second transmitter is to receive the input signal, process the input signal to generate a second transmit signal, and couple the second transmit signal into an input path of the receiver,

the noise correction circuit is to generate a correction signal and to couple the correction signal into an output path of the receiver, and

the input path of the receiver is between a baseband source and the receiver, and the output path of the receiver is different from the input path of the receiver.

2. The full duplex radio of claim 1, wherein the second transmitter comprises:

a filter to receive the input signal and to filter the input signal; and

an adaptation engine to receive an output from the receiver, identify components of the first transmit signal in the output from the receiver, and modify filter coefficients of the filter based on the identified components of the first transmit signal.

3. The full duplex radio of claim 1, wherein the noise correction circuit is to receive the input signal, and the correction signal is based on the input signal.

4. The full duplex radio of claim 3, wherein the correction signal is an analog signal, and the noise correction circuit is to, as part of coupling the correction signal into the output path of the receiver, couple the correction signal into a receiver signal path upstream of an analog to digital converter of the receiver.

5. The full duplex radio of claim 3, wherein the correction signal is a digital signal, and the noise correction circuit is to, as part of coupling the correction signal into the output path of the receiver, couple the correction signal into a receiver signal path downstream of an analog to digital converter of the receiver.

6. The full duplex radio of claim 3, where the noise correction circuit is to, as part of generation of a correction signal, monitor one or more signals within the receiver and adapt the correction signal based on the one or more signals.

7. The full duplex radio of claim 1, wherein:

the receiver is a first receiver;

the full duplex radio further includes a second receiver; and

the noise correction circuit is to receive an output from the second receiver, process the output of the second receiver to generate the correction signal, and couple the correction signal into the output path of the first receiver.

8. The full duplex radio of claim 1, wherein the first transmitter transmits at a first frequency, the receiver receives at the first frequency, and the first transmitter and the receiver can operate concurrently.

9. The full duplex radio of claim 1, further comprising:

a white space detector to detect an unused frequency band within a predetermined part of a frequency spectrum, and to adapt the first transmitter and the receiver to operate at the unused frequency band.

10. The full duplex radio of claim 1, wherein the full duplex radio is a multiple input multiple output (MIMO) radio.

11. The full duplex radio of claim 1, wherein the full duplex radio is part of a mobile telephony unit.

12. The full duplex radio of claim 1, wherein the full duplex radio is part of a machine-to-machine communication system.