Independent and Concurrent Automatic Gain Control for Wireless Communication and Spectral Intelligence

• US 20150056936A1
• Filed: 08/22/2013
• Published: 02/26/2015
• Est. Priority Date: 08/22/2013
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Rangarajan, Raghuram, Kloper, David, Stager, Paul J.
• Granted Patent: US 9,544,041 B2
• Time in Patent Office: Days
• US Class Current: 455/140
• CPC Class Codes: H03G 3/3078 Circuits generating control signals for digitally modulated signals
• CPC Class Codes: H04B 7/0817 with multiple receivers and antenna path selection

Abstract

A set of receiver path circuits is allocated for processing a radio-frequency (RF) signal provided by receive antennas coupled to the receiver path circuits. The RF signal may belong to a first signal class, such as Wi-Fi. A first gain control signal is applied to each of the allocated receiver path circuits to condition a signal level of the RF signal for the first signal class. A second gain control signal is applied to another set of receiver path circuits coupled to the receive antennas to condition the RF signal of a second signal class. First receive gain control signals are generated from the RF signals of the first signal class by the allocated set of the receiver path circuits. The first receive gain control signals are configured to optimize the signal level for processing the first signal class. A second receive gain control signal is generated to optimize the signal level of the RF signal for the second signal class.

Claims

1. A method comprising:

allocating, from a plurality of receiver path circuits coupled to one or more receive antennas of a wireless receiver, a first set of receiver path circuits for processing a radio-frequency (RF) signal from the receive antennas into a first receive signal of a first signal class;

applying a first gain control signal to each of the allocated receiver path circuits to condition a signal level of the RF signal for the processing thereof into the first receive signal;

applying a second gain control signal to a second set of receiver path circuits to condition the signal level of the RF signal for processing thereof into a second receive signal of a second signal class distinct from the first signal class;

reallocating the receiver path circuits in response to a determination from either of the first and second receive signals that a corresponding one of the first and second signal classes is a wireless communication signal class associated with a wireless network protocol and the corresponding first and second receive signals is a wireless communication signal; and

modifying the first or second gain control signal applied to the reallocated receiver path circuits to optimize the signal level of the RF signal for processing thereof into the communication signal.

2. The method of claim 1, further comprising generating the first gain control signal independently of the second gain control signal.

3. The method of claim 2, further comprising:

generating the first gain control signal in accordance with training data contained in the RF signal; and

generating the second gain control signal exclusively of the training data.

4. The method of claim 1, further comprising:

converting the first receive signal into a baseband signal that can be processed in accordance with the wireless network protocol; and

processing the second receive signal exclusively of requirements of the wireless network protocol.

5. The method of claim 4, wherein processing the second receive signal further comprises performing spectral intelligence processing on the second receive signal.

6. The method of claim 1, further comprising:

determining from the wireless communication signal processed by the reallocated set of receiver path circuits that the RF signal can be classified into a second wireless communication signal class;

reallocating the receiver path circuits for processing the RF signal of the second wireless communication signal class; and

applying a fourth gain control signal to the reallocated receiver path circuits to optimize the signal level of the RF signal for processing thereof into the second wireless communication signal class.

7. The method of claim 6, wherein the wireless communication signal class is an IEEE 802.11 signal class and the second wireless communication signal class is a high-throughput (HT) IEEE 802.11 signal class or a very-high-throughput (VHT) signal class.

8. The method of claim 6, further comprising:

detecting an indication of an end-of-packet in the receiver signal generated from the RF signal of the second wireless communication signal class;

reallocating the set of receiver path circuits into the first and second sets of receiver path circuits;

applying the first gain control signal to each of the first set of receiver path circuits to condition the signal level of the RF signal for processing into the first receive signal; and

applying the second gain control signal to the second set of receiver path circuits to condition the signal level of the RF signal for processing into the second receive signal.

9. The method of claim 1, wherein reallocating the set of receiver path circuits comprises:

resetting the first or second gain control signal to a predetermined signal state for any of the receiver path circuits reallocated to process the RF signal into the communication signal;

allocating the receiver path circuits for which the first or second gain control signal was reset to process the RF signal into the communication signal; and

applying the third gain control signal to the receiver path reallocated to process the RF signal into the communication signal.

10. The method of claim 1, wherein reallocating the receiver path circuits comprises reallocating all receiver path circuits in the wireless receiver to process the RF signal into the communication signal.

11. An apparatus comprising:

a set of one or more receive antennas to detect a radio frequency (RF) signal;

a plurality of receiver path circuits coupled to the receive antennas to independently process the RF signal into one or more receive signals;

a plurality of control loop circuits to convey automatic gain control (AGC) signals to and from each of the receiver path circuits; and

a processor coupled to the plurality of receiver path circuits and to plurality of control loop circuits, and configured to;

allocate a first set of receiver path circuits for processing the RF signal into a first receive signal of a first signal class;

apply a first gain control signal to each of the allocated receiver path circuits to condition a signal level of the RF signal for the processing thereof into the first receive signal;

apply a second gain control signal to a second set of receiver path circuits to condition the signal level of the RF signal for processing thereof into a second receive signal of a second signal class distinct from the first signal class;

reallocate the receiver path circuits in response to a determination from either of the first and second receive signals that a corresponding one of the first and second signal classes is a wireless communication signal class associated with a wireless network protocol and the corresponding first and second receive signals is a wireless communication signal; and

modify the first or second gain control signal applied to the reallocated receiver path circuits to optimize the signal level of the RF signal for processing thereof into the communication signal.

12. The apparatus of claim 11, wherein the processor is further configured to:

determine from the wireless communication signal processed by the reallocated set of receiver path circuits that the RF signal can be classified into a second wireless communication signal class;

reallocate the receiver path circuits for processing the RF signal of the second wireless communication signal class; and

apply a fourth gain control signal to the reallocated receiver path circuits to optimize the signal level of the RF signal for processing thereof into the second wireless communication signal class.

13. The apparatus of claim 11, wherein the wireless communication signal class is an IEEE 802.11 signal class and the second wireless communication signal class is a high-throughput (HT) IEEE 802.11 signal class or a very-high-throughput (VHT) signal class.

14. The apparatus of claim 11, wherein the processor is further configured to:

detect an indication of an end-of-packet in the receiver signal generated from the RF signal of the second wireless communication signal class;

reallocate the set of receiver path circuits into the first and second sets of receiver path circuits;

apply the first gain control signal to each of the first set of receiver path circuits to condition the signal level of the RF signal for processing into the first receive signal; and

apply the second gain control signal to the second set of receiver path circuits to condition the signal level of the RF signal for processing into the second receive signal.

15. The apparatus of claim 14, wherein the processor is further configured to:

receive an indication that another receive signal of the wireless communication signal class is expected on an RF signal within a time interval;

postpone the reallocating of the receiver path circuits into the first and second sets of receiver path circuits for at least the time interval.

16. A tangible, non-transitory computer-readable medium having instructions encoded thereon that, when executed by a processor, configure the processor to:

allocate, from a plurality of receiver path circuits coupled to one or more receive antennas of a wireless receiver, a first set of receiver path circuits for processing a radio-frequency (RF) signal from the receive antennas into a first receive signal of a first signal class;

apply a first gain control signal to each of the allocated receiver path circuits to condition a signal level of the RF signal for the processing thereof into the first receive signal;

apply a second gain control signal to a second set of receiver path circuits to condition the signal level of the RF signal for processing thereof into a second receive signal of a second signal class distinct from the first signal class;

reallocate the receiver path circuits in response to a determination from either of the first and second receive signals that a corresponding one of the first and second signal classes is a wireless communication signal class associated with a wireless network protocol and the corresponding first and second receive signals is a wireless communication signal; and

modify the first or second gain control signal applied to the reallocated receiver path circuits to optimize the signal level of the RF signal for processing thereof into the communication signal.

17. The computer-readable medium of claim 16, having further instructions encoded thereon that, when executed by the processor, configure the processor to:

determine from the wireless communication signal processed by the reallocated set of receiver path circuits that the RF signal can be classified into a second wireless communication signal class;

reallocate the receiver path circuits for processing the RF signal of the second wireless communication signal class; and

apply a fourth gain control signal to the reallocated receiver path circuits to optimize the signal level of the RF signal for processing thereof into the second wireless communication signal class.

18. The computer-readable medium of claim 17, having further instructions encoded thereon that, when executed by the processor, configure the processor to:

generate the first gain control signal independently of the second gain control signal.

19. The computer-readable medium of claim 17, further comprising instructions that configure the processor to generate the first gain control signal independently of the second gain control signal.

20. The computer-readable medium of claim 19, further comprising instructions that configure the processor to:

generate the first gain control signal in accordance with training data contained in the RF signal; and

generate the second gain control signal exclusively of the training data.