High-Capacity FHSS-MA Devices and Methods

• US 20160277064A1
• Filed: 03/17/2015
• Published: 09/22/2016
• Est. Priority Date: 03/17/2015
• Status: Active Grant

• Current Assignee: Shai Waxman
• Original Assignee: Shai Waxman
• Inventors: WAXMAN, Shai
• Granted Patent: US 10,141,974 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 2001/7152 with means for suppressing interference
• CPC Class Codes: H04B 7/2621 using frequency division multiple access [FDMA] H04B7/2615 takes precedence

Abstract

A frequency-hopped spread-spectrum multiple-access (FHSS-MA) wideband transceiver may support frequency-division multiple-access (FDMA) functionality by including a plurality of digital chains corresponding to FHSS-MA physical channels, individually and dynamically compensated for in-phase/quadrature imbalance in the transmit and/or receive portion. A FHSS-MA transceiver supporting FDMA functionality may coordinate FH sequence selection among FHSS physical channels to minimize inter-channel interference while also supporting legacy FHSS-enabled devices (e.g., Bluetooth®). The FHSS-MA transceiver may be incorporated into a wireless bridge device to facilitate low-latency communications over wireless local-area networks (WLANs), wireless wide-area networks (WWANs) or broadcast, with multiple FHSS-enabled devices that may be paired with the wireless bridge device using FHSS-MA channels. The wireless bridge device may enable a FHSS-enabled device to re-pair with a personal device. Such wireless bridge devices may be networked into a wireless bridge network that may increase the number of FHSS-enabled devices that may be accommodated and/or increase coverage range.

Claims

1. A frequency-hopped spread-spectrum multiple-access (FHSS-MA) communication apparatus, comprising:

a plurality of digital receive chains, each digital receive chain coupled to receive a pair of common digitized intermediate-frequency (IF) in-phase (I) and quadrature (Q) components of a received radio-frequency (RF) FHSS-MA signal, wherein a respective digital receive chain includes;

an I/Q imbalance correction circuit configured to reduce mismatch between the digitized IF I and Q components; and

a mixer configured to down-convert I and Q outputs of the I/Q imbalance correction circuit to zero-IF (ZIF) by mixing the I and Q outputs of the I/Q imbalance correction circuit with a respective frequency hopping waveform corresponding to the respective digital receive chain and distinct from frequency hopping waveforms corresponding to other ones of the plurality of digital receive chains, to produce ZIF I and Q components.

2. The apparatus of claim 1, further comprising a carrier local oscillator (LO) leakage suppression circuit disposed prior to the plurality of digital receive chains and configured to suppress carrier (LO) leakage in the digitized IF I and Q components of the received RF FHSS-MA signal.

3. The apparatus of claim 2, wherein the carrier (LO) leakage suppression circuit includes a coefficient memory configured to output coefficients to be combined with the digitized IF I and Q components, wherein the coefficients are determined as a function of a frequency used to down-convert the RF FHSS-MA signal to IF.

4. The apparatus of claim 1, wherein the mixer is a digital mixer, and wherein the respective frequency hopping waveform is a digitized frequency hopping waveform.

5. The apparatus of claim 1, wherein the I/Q imbalance correction circuit is configured to perform I/Q imbalance correction as a function of a frequency used to down-convert the FHSS-MA signal to IF and as a function of frequencies of the respective frequency hopping waveform.

6. The apparatus of claim 5, wherein the I/Q imbalance correction circuit is configured to compensate the imbalance between the I and Q components using coefficients, wherein the coefficients are determined as a function of the frequency used to down-convert the FHSS-MA signal to IF and as a function of the frequencies of the respective frequency hopping waveform.

7. The apparatus of claim 1, wherein a respective digital receive chain further includes a filtering and decimation stage configured to filter and decimate the ZIF I and Q components.

8. A frequency-hopped spread-spectrum multiple-access (FHSS-MA) communication apparatus, comprising:

a plurality of digital transmit chains, each digital transmit chain coupled to receive respective digitized zero-intermediate frequency (ZIF) in-phase (I) and quadrature (Q) components, wherein a respective digital transmit chain includes;

a mixer configured to up-convert the respective ZIF I and Q components to digital frequency-hopped intermediate frequency (IF) I and Q components by mixing the respective ZIF I and Q components with a respective digitized frequency hopping waveform corresponding to the respective digital transmit chain and distinct from frequency hopping waveforms corresponding to other ones of the plurality of digital transmit chains, to produce respective digitized frequency-hopped IF I and Q components; and

an I/Q imbalance correction circuit configured to reduce mismatch between I and Q components to be up-converted to a radio-frequency (RF) carrier frequency, which are formed based at least in part on the respective digitized frequency-hopped IF I and Q components, wherein the I/Q imbalance correction circuit is configured to output respective corrected IF I and Q components.

9. The apparatus of claim 8, further comprising a combiner configured to combine the respective corrected IF I and Q components to obtain combined digitized IF FHSS-MA I and Q components, and a carrier leakage suppression circuit coupled to receive the combined digitized IF FHSS-MA I and Q components and to output leakage-suppressed digitized IF I and Q components.

10. The apparatus of claim 9, wherein the carrier leakage suppression circuit includes a coefficient memory configured to output coefficients to be combined with the combined digitized IF FHSS-MA I and Q components, wherein the coefficients are determined as a function of the RF carrier frequency.

11. The apparatus of claim 8, wherein the I/Q imbalance correction circuit is configured to perform I/Q imbalance correction as a function of an RF carrier frequency and frequencies of the respective digitized frequency hopping waveform.

12. The apparatus of claim 11, wherein the I/Q imbalance correction circuit includes a coefficient memory configured to output coefficients to be used to reduce the mismatch, wherein the coefficients are determined as a function of the RF carrier frequency and as a function of the frequencies of the respective digitized frequency hopping waveform frequency.

13. The apparatus of claim 8, wherein a respective digital transmit chain further includes an interpolation and filtering stage configured to interpolate and filter the respective digitized ZIF I and Q components prior to the mixer.

14. The apparatus of claim 8, further comprising:

a plurality of digital receive chains, each digital receive chain coupled to receive a pair of common digitized intermediate-frequency (IF) in-phase (I) and quadrature (Q) components of a received radio-frequency (RF) FHSS-MA signal, wherein a respective digital receive chain includes;

an I/Q imbalance correction circuit configured to reduce mismatch between the digitized IF I and Q components; and

a mixer configured to down-convert I and Q outputs of the I/Q imbalance correction circuit to zero-IF (ZIF) by mixing the I and Q outputs of the I/Q imbalance correction circuit with a respective frequency hopping waveform corresponding to the respective digital receive chain and distinct from frequency hopping waveforms corresponding to other ones of the plurality of digital receive chains, to produce ZIF I and Q components.

15. A frequency-hopped spread-spectrum multiple-access (FHSS-MA) communication method, comprising:

processing digitized intermediate-frequency (IF) in-phase (I) and quadrature (Q) components, obtained from a received radio-frequency (RF) FHSS-MA signal, a plurality of times, corresponding to a plurality of different frequency hopping waveforms, wherein the processing includes;

performing I/Q imbalance correction to reduce mismatch between the digitized IF I and Q components; and

down-converting I and Q outputs of the I/Q imbalance correction to zero-IF (ZIF) by mixing the I and Q outputs of the I/Q imbalance correction with a respective frequency hopping waveform of the plurality of different frequency hopping waveforms, to produce ZIF I and Q components.

16. The method of claim 15, further comprising:

performing carrier leakage suppression on the digitized IF I and Q components prior to said processing.

17. The method of claim 15, wherein said processing comprises multiple parallel instances of said performing I/Q imbalance correction and said down-converting, which parallel instances correspond to respective frequency hopping waveforms of the plurality of different frequency hopping waveforms.

18. The method of claim 15, wherein performing I/Q imbalance correction includes using coefficients generated based on an RF carrier frequency of a local oscillator (LO) waveform used to down-convert the RF FHSS-MA signal to IF and frequencies of the respective frequency hopping waveform.

19. A frequency-hopped spread-spectrum multiple-access (FHSS-MA) communication method, comprising:

processing received digitized zero-intermediate-frequency (ZIF) in-phase (I) and quadrature (Q) signal components a plurality of times, corresponding to a plurality of different frequency hopping waveforms, wherein the processing includes;

up-converting the digitized ZIF I and Q components by mixing the digitized ZIF I and Q components with a respective frequency hopping waveform of the plurality of different frequency hopping waveforms, to produce digitized intermediate-frequency (IF) I and Q components; and

performing I/Q imbalance correction to reduce mismatch between the digitized IF I and Q components.

20. The method of claim 19, further comprising:

combining the resulting pluralities of digitized IF I components and digitized IF Q components and performing carrier local oscillator (LO) leakage suppression on the combined digitized IF FHSS-MA I and Q components.

21. The method of claim 19, wherein said processing comprises multiple parallel instances of said up-converting and performing I/Q imbalance correction, which parallel instances and correspond to respective frequency hopping waveforms of the plurality of different frequency hopping waveforms.

22. The method of claim 19, wherein performing I/Q imbalance correction includes using coefficients generated based on a local oscillator (LO) radio-frequency (RF) carrier frequency used to up-convert a resulting IF waveform and frequencies of the respective frequency hopping waveform.

23. A method of mitigating inter-channel interference in a frequency-hopped spread-spectrum multiple-access (FHSS-MA) communication system, the method including:

based on a common reference clock, synchronizing time-division duplex operations between at least one master FHSS-MA device and multiple FHSS-MA slave devices to avoid time-overlap between the devices transmission and reception; and

coordinating frequency-hopping (FH) sequence selection between the at least one master FHSS-MA device and the multiple FHSS-MA slave devices to avoid time and frequency overlap between device transmission.

24. The method of claim 23, wherein said coordinating FH sequence selection includes assigning to a respective FHSS-MA slave device a respective cyclic frequency offset (CFO) to offset a FH sequence common to a plurality of the multiple FHSS-MA slave devices.

25. The method of claim 23, wherein said coordinating FH sequence selection includes assigning one or more respective cyclic clock offsets (CCO) to one or more respective ones of the multiple FHSS-MA slave devices.

26. The method of claim 25, wherein the one or more respective ones of the multiple FHSS-MA slave devices comprise one or more FHSS-MA slave devices that lack a capability to offset a common FH sequence based on a CFO.

27. The method of claim 23, wherein said coordinating FH sequence selection includes assigning a FH sequence having a least number of frequencies in common with other FHSS physical channels supported by the FHSS-MA communication system for use by one or more of the multiple FHSS-MA slave devices that lack a capability to offset a common FH sequence based on a CFO.

28. The method of claim 23, wherein said coordinating FH sequence selection further comprises using adaptive frequency hopping (AFH).

29. A memory apparatus having stored therein software instructions configured to cause one or more processors logic circuits, or both to implement operations for mitigating inter-channel interference in a frequency-hopped spread-spectrum multiple-access (FHSS-MA) system, the operations including:

based on a common reference clock, synchronizing time-division duplex operations between at least one master FHSS-MA device and multiple FHSS-MA slave devices to avoid time-overlap between transmission and reception; and

coordinating frequency-hopping (FH) sequence selection between the at least one master FHSS-MA device and the multiple FHSS-MA slave devices.

30. The memory apparatus of claim 29, wherein said coordinating FH sequence selection includes assigning to a respective FHSS-MA slave device a respective cyclic frequency offset (CFO) to offset a FH sequence common to a plurality of the multiple FHSS-MA slave devices.

31. The memory apparatus of claim 29, wherein said coordinating FH sequence selection includes assigning one or more respective cyclic clock offsets (CCO) to one or more respective ones of the multiple FHSS-MA slave devices.

32. The memory apparatus of claim 31, wherein the one or more respective ones of the multiple FHSS-MA slave devices comprise one or more FHSS-MA slave devices that lack a capability to offset a common FH sequence based on a CFO.

33. The memory apparatus of claim 29, wherein said coordinating FH sequence selection includes assigning a FH sequence having a least number of frequencies in common with other FHSS physical channels supported by the FHSS-MA communication system for use by one or more of the multiple FHSS-MA slave devices that lack a capability to offset a common FH sequence based on a CFO.

34. The memory apparatus of claim 29, wherein said coordinating FH sequence selection further comprises using adaptive frequency hopping (AFH).

35. An apparatus in a frequency-hopped spread-spectrum multiple-access (FHSS-MA) system, the apparatus including:

at least one processor or logic circuit, or a combination of at least one processor and at least one logic circuit; and

the memory apparatus of claim 29.

36. A method of mitigating inter-channel interference, implemented in a frequency-hopped spread-spectrum multiple-access (FHSS-MA) slave communication device, the method including:

synchronizing a device clock to a common reference clock of a FHSS-MA communication system;

based on the common reference clock, coordinating time-division duplexing operations between the FHSS-MA communication device and a FHSS-MA master communication device to avoid time-overlap between transmission and reception relative to at least one other FHSS-MA slave communication device; and

performing frequency-hop (FH) sequence selection based on FHSS-MA coordination information from the FHSS-MA master communication device.

37. The method of claim 36, wherein the FHSS-MA coordination information comprises a cyclic frequency offset (CFO), and wherein said performing FH sequence selection includes offsetting, based on the CFO, a common FH sequence assigned to the FHSS-MA slave communication device and at least one other FHSS-MA slave communication device.

38. The method of claim 36, wherein the FHSS-MA coordination information comprises a cyclic clock offset (CCO), and wherein said performing FH sequence selection includes offsetting the common reference clock based on the CCO to obtain an offset clock and performing FH sequence selection based on the offset clock.

39. The method of claim 36, wherein the FHSS-MA coordination information further comprises an adaptive frequency hopping (AFH) channel map, and wherein said FH sequence selection is performed subject to the AFH channel map.

40. A frequency-hopped spread-spectrum multiple-access (FHSS-MA) slave communication apparatus, including:

a frequency-hop (FH) sequence selection module configured to perform FH sequence selection based on FHSS-MA coordination information received from a FHSS-MA master communication device;

wherein the FHSS-MA slave communication apparatus is configured to coordinate to a common reference clock received from the FHSS-MA master communication device; and

wherein the FHSS-MA slave communication apparatus is further configured to coordinate time-division duplexing operation, based on the master clock, to avoid time-overlap between transmission and reception relative to at least one other FHSS-MA slave communication device.

41. The apparatus of claim 40, wherein the FH sequence selection module includes:

at least one mapping table; and

one or more logic components configured to select a FH sequence from the at least one mapping table, based at least in part of the FHSS-MA coordination information.

42. The apparatus of claim 41, wherein the at least one mapping table includes a first mapping table and a second mapping table, wherein the second mapping table corresponds to an adaptive frequency hopping (AFH) mapping table that reflects an AFH channel map received from the FHSS-MA master communication device.

43. The apparatus of claim 42, further comprising a selection device configured to select output of the first mapping table or the second mapping table.

44. The apparatus of claim 41, wherein the one or more logic components comprise a cyclic frequency offset (CFO) device, wherein the FHSS-MA coordination information includes a CFO.

45. The apparatus of claim 44, wherein the CFO device comprises at least one adder configured to add the CFO to at least one selection index as an offset.

46. The apparatus of claim 41, wherein the apparatus is assigned a FH sequence in common with one or more other FHSS-MA slave communication apparatuses coordinated by the FHSS-MA master communication device.

47. The apparatus of claim 41, further comprising a cyclic clock offset (CCO) device configured to offset the common reference clock based on a CCO received from the FHSS-MA master communication device.