Approach for spectrum analysis in a receiver

• US 8,023,575 B2
• Filed: 01/31/2007
• Issued: 09/20/2011
• Est. Priority Date: 06/13/2006
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Bandspeed, Inc. (Broadcom, Inc.)
• Inventors: Ding, Ming, Morton, John “Jack”, Jones, Ben
• Primary Examiner(s): Fan; Chieh M
• Assistant Examiner(s): Lee; Siu M
• Application Number:
  US11/701,560
• Publication Number:
  US 20070297524A1
• Time in Patent Office: 1,693 Days
• Field of Search: 375/260, 375/267, 375/347, 375/316, 375/346, 375/227, 370/210, 455/150, 324/76.11, 324/76.19, 324/73.22, 702/74, 702/75, 702/78, 702/77
• US Class Current: 375/260
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01

Abstract

A wireless communications apparatus that it is useable as a spectrum analyzer and as a wireless receiver. The wireless communications apparatus has a radio circuit that is configured to receive EM radiation. Signal processing logic receives signals from the radio circuit based on the EM radiation. The signal processing logic has a receiver operational mode that processes the signals in accordance with a communication protocol and outputs data encoded in the signals to a host processor. The signal processing logic has a spectrum analyzer operational mode that generates frequency domain data and passes the frequency domain data to the host processor. The frequency domain data describe strength versus frequency of the EM radiation. The host processes the data in accordance with the configuration currently in use. Therefore, the wireless communications apparatus operates as a receiver in one operational mode and as a real-time spectrum analyzer in another operational mode.

Claims

1. A device, comprising:

a first operational mode in which the device is operable to use a fast Fourier transform (FFT) component to process, in accordance with a communication protocol, first signals received by the device to determine communication data encoded in the first signals and to output the communication data;

a second operational mode in which the device is operable to generate and output frequency domain data representing second signals received by the device, wherein the frequency domain data includes strength of the second signals versus frequency of the second signals and wherein in the second operational mode the device is configured to use the FFT component to process the second signals and to use logic that packetizes data that has been processed by the FFT component, wherein the frequency domain data are output in packets; and

logic that is operable to cause the device to operate in the first operational mode and the second operational mode, wherein the second operational mode is realized by selective bypassing of at least one portion of components used in the first operational mode.

2. The device of claim 1, wherein the logic that is operable to cause the device to operate in the first operational mode and the second operational mode is operable to reconfigure the device between a first configuration and a second configuration.

3. The device of claim 1, wherein in the first operational mode the device is configured to use packet detection logic to detect packets in the first signals received by the device.

4. The device of claim 3, wherein in the second operational mode the device bypasses the packet detection logic.

5. The device of claim 1, further comprising media access control (MAC) logic that in the second operational mode is operable to receive the packets and pass the packets to a host without performing media access control functions.

6. The device of claim 1, wherein in the first operational mode the device operates as an orthogonal frequency division multiplexed (OFDM) receiver.

7. The device of claim 1, wherein the logic that is operable to cause the device to operate in the first operational mode and the second operational mode is operable to switch circuit datapaths to switch between the first operational mode and the second operational mode.

8. The device of claim 1, wherein in the first operational mode the device comprises a constellation demapper to demap symbols in orthogonal frequency division multiplexed (OFDM) signals and wherein in the second operational mode the device is configured to bypass the constellation demapper.

9. A wireless communications apparatus comprising:

a radio circuit that is configured to receive electromagnetic radiation;

a host processor;

signal processing logic coupled to the radio circuit to receive signals based on the electromagnetic radiation; and

logic that is operable to cause the signal processing logic to operate in a first operational mode and a second operational mode;

wherein, in the first operational mode, the signal processing logic is operable to process the signals in accordance with a communication protocol to determine communication data encoded in the signals and to output the communication data to the host processor, wherein in the first operational mode the signal processing logic comprises packet detection logic to detect packets in the signals;

wherein, in the second operational mode, the signal processing logic is operable to generate frequency domain data based on the signals and to pass the frequency domain data to the host processor, wherein the frequency domain data describe strength versus frequency of the electromagnetic radiation, wherein in the second operational mode the signal processing logic is configured to bypass the packet detection logic;

wherein, in the first operational mode, the host is operable to process the communication data to operate as a receiver; and

wherein, in the second operational mode, the host is operable to process the frequency domain data to operate as a spectrum analyzer.

10. The wireless communications apparatus of claim 9, wherein the logic that is operable to cause the signal processing logic to operate in the first operational mode and the second operational mode is operable to change the signal processing logic between a first configuration and a second configuration.

11. The apparatus of claim 9, wherein:

the signal processing logic includes a fast Fourier transform (FFT) component to process the signals in the first operational mode; and

the signal processing logic includes the fast Fourier transform component to process the signals in the second operational mode.

12. The apparatus of claim 11, wherein in the second operational mode the signal processing logic comprises logic that packetizes data that has been processed by the fast Fourier transform component, wherein the frequency domain data are output to the host processor in packets.

13. The apparatus of claim 12, wherein the apparatus comprises media access control (MAC) logic that in the second operational mode is operable to receive the packets and pass the packets to the host processor without performing media access control functions.

14. The apparatus of claim 9, wherein in the first operational mode the apparatus operates as an orthogonal frequency division multiplexed (OFDM) receiver.

15. The apparatus of claim 9, wherein the logic that is operable to cause the signal processing logic to operate in the first operational mode and the second operational mode is operable to switch circuit datapaths to change between the first operational mode and the second operational mode.

16. A method comprising:

operating signal processing logic in a first operational mode in which the signal processing logic is operable to process orthogonal frequency division multiplexed (OFDM) signals and to transfer processed OFDM data to a host, wherein operating the signal processing logic in the first operational mode includes detecting packets in signals received by the signal processing logic;

in response to a control signal from the host, causing the signal processing logic to operate in a second operational mode that is operable to generate frequency domain data representing general electromagnetic radiation and to pass the frequency domain data to the host, wherein causing the signal processing logic to operate in the second operational mode comprises bypassing logic that detects packets;

while the signal processing logic is in the first operational mode, the host processing the processed OFDM data; and

while the signal processing logic is in the second operational mode, the host processing the frequency domain data to operate as a spectrum analyzer.

17. The method of claim 16, further comprising switching circuit datapaths to switch from the first operational mode to the second operational mode.

18. A method comprising:

operating signal processing logic in a first operational mode in which the signal processing logic is operable to process orthogonal frequency division multiplexed (OFDM) signals and to transfer processed OFDM data to a host, while in the first operational mode, processing the OFMD signals using a fast Fourier transform (FFT) component;

in response to a control signal from the host, causing the signal processing logic to operate in a second operational mode that is operable to generate frequency domain data representing general electromagnetic radiation and to pass the frequency domain data to the host, while in the second operational mode, processing signals based on the general electromagnetic radiation using the FFT component;

while the signal processing logic is in the first operational mode, the host processing the processed OFDM data; and

while the signal processing logic is in the second operational mode, the host processing the frequency domain data to operate as a spectrum analyzer.

19. A method comprising:

operating signal processing logic in a first operational mode in which the signal processing logic is operable to process orthogonal frequency division multiplexed (OFDM) signals and to transfer processed OFDM data to a host;

in response to a control signal from the host, causing the signal processing logic to operate in a second operational mode that is operable to generate frequency domain data representing general electromagnetic radiation and to pass the frequency domain data to the host, while in the second operational mode, packetizing the frequency domain data;

while the signal processing logic is in the first operational mode, the host processing the processed OFDM data; and

while the signal processing logic is in the second operational mode, the host processing the frequency domain data to operate as a spectrum analyzer.

20. A method comprising:

operating signal processing logic in a first operational mode in which the signal processing logic is operable to process orthogonal frequency division multiplexed (OFDM) signals and to transfer processed OFDM data to a host, while in the first operational mode, performing media access control functions using a media access controller (MAC);

in response to a control signal from the host, causing the signal processing logic to operate in a second operational mode that is operable to generate frequency domain data representing general electromagnetic radiation and to pass the frequency domain data to the host, while in the second operational mode, using the MAC in a pass through mode in which media access control functions are not performed;

while the signal processing logic is in the first operational mode, the host processing the processed OFDM data; and

while the signal processing logic is in the second operational mode, the host processing the frequency domain data to operate as a spectrum analyzer.

21. A method comprising:

operating signal processing logic in a first operational mode in which the signal processing logic is operable to process orthogonal frequency division multiplexed (OFDM) signals and to transfer processed OFDM data to a host;

in response to a control signal from the host, causing the signal processing logic to operate in a second operational mode that is operable to generate frequency domain data representing general electromagnetic radiation and to pass the frequency domain data to the host, and wherein the signal processing logic operating in the second operational mode includes one or more of bypassing de-interleaving that is used in the first operational mode, bypassing decoding that is used in the first configuration, bypassing de-scrambling that is used in the first configuration and bypassing cyclic prefix removal logic that is used in the first configuration;

while the signal processing logic is in the first operational mode, the host processing the processed OFDM data; and

while the signal processing logic is in the second operational mode, the host processing the frequency domain data to operate as a spectrum analyzer.

22. A wireless communications apparatus comprising:

a radio circuit that is configured to receive electromagnetic radiation;

a host processor;

signal processing logic coupled to the radio circuit to receive signals based on the electromagnetic radiation; and

logic that is operable to cause the signal processing logic to operate in a first operational mode and a second operational mode;

wherein, in the first operational mode, the signal processing logic is operable to process the signals in accordance with a communication protocol to determine communication data encoded in the signals and to output the communication data to the host processor and wherein in the first operational mode the signal processing logic is configured to use a constellation demapper to demap symbols in orthogonal frequency division multiplexed (OFDM) signals;

wherein, in the second operational mode, the signal processing logic is operable to generate frequency domain data based on the signals and to pass the frequency domain data to the host processor, wherein the frequency domain data describe strength versus frequency of the electromagnetic radiation and wherein in the second operational mode the signal processing logic is configured to bypass the constellation demapper;

wherein, in the first operational mode, the host processor is operable to process the communication data to operate as a receiver; and

wherein, in the second operational mode, the host processor is operable to process the frequency domain data to operate as a spectrum analyzer.

23. The wireless communications apparatus of claim 22, wherein the logic that is operable to cause the signal processing logic to operate in the first operational mode and the second operational mode is operable to change the signal processing logic between a first configuration and a second configuration.

24. The apparatus of claim 22, wherein in the second operational mode the signal processing logic generates the frequency domain data in packet form.

25. The apparatus of claim 24, wherein the apparatus comprises media access control (MAC) logic that in the second operational mode is operable to receive the frequency domain data in packet form and pass the frequency domain data in packet form to the host processor without performing media access control functions.

26. The apparatus of claim 22, wherein in the first operational mode the apparatus operates as an orthogonal frequency division multiplexed (OFDM) receiver.

27. The apparatus of claim 22, wherein the logic that is operable to cause the signal processing logic to operate in the first operational mode and the second operational mode is operable to switch circuit datapaths to change between the first operational mode and the second operational mode.

28. The apparatus of claim 22, wherein in the first operational mode the signal processing logic is configured to use a constellation demapper to demap symbols in orthogonal frequency division multiplexed (OFDM) signals and wherein in the second operational mode the signal processing logic is configured to bypass the constellation demapper.

29. A wireless communications apparatus comprising:

a radio circuit that is configured to receive electromagnetic radiation;

a host processor;

signal processing logic coupled to the radio circuit to receive signals based on the electromagnetic radiation, wherein the signal processing logic includes a fast Fourier transform (FFT) component; and

logic that is operable to cause the signal processing logic to operate in a first operational mode and a second operational mode;

wherein, in the first operational mode, the signal processing logic is operable to use the FFT component to process the signals in accordance with a communication protocol to determine communication data encoded in the signals and to output the communication data to the host processor;

wherein, in the second operational mode, the signal processing logic is operable to use the FFT component to generate frequency domain data based on the signals and to pass the frequency domain data to the host processor, wherein the frequency domain data describe strength versus frequency of the electromagnetic radiation;

wherein, in the first operational mode, the host processor is operable to process the communication data to operate as a receiver; and

wherein, in the second operational mode, the host processor is operable to process the frequency domain data to operate as a spectrum analyzer.