Intelligent backhaul radio with receiver performance enhancement

• US 9,055,463 B2
• Filed: 07/22/2014
• Issued: 06/09/2015
• Est. Priority Date: 08/17/2011
• Status: Active Grant

• Current Assignee: COMS IP Holdings LLC
• Original Assignee: CBF Networks, Inc. (COMSovereign Holding Corp.)
• Inventors: Negus, Kevin J.
• Primary Examiner(s): Ebrahim, Anez
• Assistant Examiner(s): Sharma, Gautam
• Application Number:
  US14/337,744
• Publication Number:
  US 20150016362A1
• Time in Patent Office: 322 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 25/005 providing two patterns of opposite direction; back to back antennas H01Q25/004 takes precedence
• CPC Class Codes: H01Q 5/50 Feeding or matching arrangements for broad-band or multi-band operation
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 2001/0408 with power amplifiers
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 25/03019 adaptive, i.e. capable of adjustment during data reception
• CPC Class Codes: H04L 27/01 Equalisers baseband equalizers at the transmitter end H04L25/03343; in analogue transmission systems H04B3/04, H04B7/005
• CPC Class Codes: H04L 27/2636 with FFT or DFT modulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] transmitter or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM]
• CPC Class Codes: H04L 27/2678 using cyclostationarities, e.g. cyclic prefix or postfix
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04W 24/02 : Arrangements for optimising operational condition
• CPC Class Codes: H04W 52/52 : using AGC [Automatic Gain Control] circuits or amplifiers
• CPC Class Codes: H04W 72/04 : Wireless resource allocation
• CPC Class Codes: H04W 72/0453 : Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 76/27 : Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 84/12 : WLAN [Wireless Local Area Networks]

Abstract

A intelligent backhaul radio is disclosed that is compact, light and low power for street level mounting, operates at 100 Mb/s or higher at ranges of 300 m or longer in obstructed LOS conditions with low latencies of 5 ms or less, can support PTP and PMP topologies, uses radio spectrum resources efficiently and does not require precise physical antenna alignment.

Claims

1. A backhaul radio comprising:

one or more demodulator cores, wherein each demodulator core is capable of demodulating one or more of a plurality of receive symbol streams to produce one or more receive data interface streams;

a plurality of receive radio frequency (RF) chains, wherein each receive RF chain is capable of converting from one of a plurality of receive RF signals to a respective one of a plurality of receive chain output signals;

a frequency selective receive path channel multiplexer, interposed between the one or more demodulator cores and at least two of the plurality of receive RF chains, wherein the frequency selective receive path channel multiplexer is capable of generating the plurality of receive symbol streams from at least two of the plurality of receive chain output signals provided by said at least two of the plurality of receive RF chains; and

an antenna array comprising;

a plurality of directive gain antenna elements; and

one or more selectable RF connections for selectively coupling certain of the plurality of directive gain antenna elements to certain of the plurality of receive RF chains, said certain of the plurality of receive RF chains including at least one receive RF chain coupled to the frequency selective receive path channel multiplexer, wherein the number of directive gain antenna elements that can be selectively coupled to receive RF chains exceeds the number of receive RF chains that can accept receive RF signals from the one or more selectable RF connections;

wherein the backhaul radio is capable of determining an opportunity for a performance enhancement that derives from setting specific selective couplings between the certain of the plurality of directive gain antenna elements and the certain of the plurality of receive RF chains.

2. The backhaul radio of claim 1, further comprising:

a radio resource controller, wherein the radio resource controller is capable of setting or causing to be set specific selective couplings between the certain of the plurality of directive gain antenna elements and the certain of the plurality of receive RF chains.

3. The backhaul radio of claim 1, wherein each one of the one or more demodulator cores comprises at least a decoder and a soft decision symbol demapper;

and wherein each one of the plurality of receive RF chains comprises at least a vector demodulator and two analog to digital converters that are capable of producing the respective one of the plurality of receive chain output signals, each said respective one of the plurality of receive chain output signals comprised of digital baseband quadrature signals.

4. The backhaul radio of claim 1, wherein the set of receive RF chains that can accept receive RF signals from the one or more selectable RF connections is divided between one subset that accepts receive RF signals from directive gain antenna elements with a first polarization and a second subset that accepts receive RF signals from directive gain antenna elements with a second polarization.

5. The backhaul radio of claim 1, wherein the directive gain antenna elements that can be selectively coupled to receive RF chains are arranged on a plurality of facets with one or more directive gain antenna elements per facet, and wherein each facet is oriented at a different azimuth angle relative to at least one other facet.

6. The backhaul radio of claim 1, wherein said determining an opportunity for a performance enhancement includes monitoring at least one of receive signal strength indication (RSSI), decoder metrics, frame check sum (FCS) failure rates, channel equalization metrics, or RF channel activity.

7. The backhaul radio of claim 2, further comprising:

a backhaul management system agent that is capable of setting or causing to be set certain policies relevant to the radio resource controller, wherein the backhaul management system agent is capable of exchanging information with other backhaul management system agents within other backhaul radios or with one or more backhaul management system servers.

8. The backhaul radio of claim 7, wherein the information that can be exchanged with said backhaul management system agent can be used at least to set or cause to be set at least one of an RF carrier frequency, a specific selective coupling between at least one of the certain of the plurality of directive gain antenna elements and at least one of the certain of the plurality of receive RF chains, or a channel bandwidth.

9. The backhaul radio of claim 1, wherein the frequency selective receive path channel multiplexer comprises at least one of a Space Division Multiple Access (SDMA) combiner or equalizer, a maximal ratio combining (MRC) combiner or equalizer, a minimum mean squared error (MMSE) combiner or equalizer, an Eigen Beam Forming (EBF) combiner or equalizer, a receive beam forming (BF) combiner or equalizer, a Zero Forcing (ZF) combiner or equalizer, a channel estimator, a Maximal Likelihood (DL) detector, an Interference Canceller (IC), a VBLAST combiner or equalizer, a Discrete Fourier Transformer (DFT), a Fast Fourier Transformer (FFT), or an Inverse Fast Fourier Transformer (IFFT).

10. The backhaul radio of claim 1 wherein said performance enhancement includes one or more of a reduced interference level within one or more of the receive symbol streams, an increased data throughput rate, an improved link diversity, an increased channel efficiency, or an increased signal to interference and noise ratio (SINR).

11. The backhaul radio of claim 1 wherein at least one of the one or more selectable RF connections comprises at least one RF switch.

12. The backhaul radio of claim 1 wherein the antenna array further comprises one or more additional RF connections that each couple a respective one of an additional certain of the plurality of directive gain antenna elements to a respective one of an additional certain of the plurality of receive RF chains.

13. The backhaul radio of claim 12 wherein at least one of the additional certain of the plurality of receive RF chains is coupled to the frequency selective receive path channel multiplexer.

14. A backhaul radio comprising:

one or more demodulator cores, wherein each demodulator core is capable of demodulating one or more of a plurality of receive symbol streams to produce one or more receive data interface streams;

a plurality of receive radio frequency (RF) chains, wherein each receive RF chain is capable of converting from one of a plurality of receive RF signals to a respective one of a plurality of receive chain output signals;

a frequency selective receive path channel multiplexer, interposed between the one or more demodulator cores and at least two of the plurality of receive RF chains, wherein the frequency selective receive path channel multiplexer is capable of generating the plurality of receive symbol streams from at least two of the plurality of receive chain output signals provided by said at least two of the plurality of receive RF chains; and

an antenna array comprising;

a plurality of directive gain antenna elements, wherein at least two of the plurality of directive gain antenna elements are each couplable or coupled to at least one of the plurality of receive RF chains coupled to the frequency selective receive path channel multiplexer; and

one or more probe-in-space antenna elements, wherein at least one of the one or more probe-in-space antenna elements has a larger azimuthal coverage pattern than any of said at least two of the plurality of directive gain antenna elements, and wherein said at least one of the one or more probe-in-space antenna elements is couplable or coupled to at least one of the plurality of receive RF chains;

wherein the backhaul radio is capable of determining an opportunity for a performance enhancement that derives from at least one of i) changing any attribute of the frequency selective receive path channel multiplexer, ii) changing, with respect to antenna elements that are couplable to more than one of the plurality of receive RF chains, at least one coupling between any of the plurality of directive gain antenna elements or the one or more probe-in-space antenna elements and any of the plurality of receive RF chains, or iii) changing at least one of an RF carrier frequency or a channel bandwidth for at least one of the plurality of receive RF chains; and

wherein said determining an opportunity for a performance enhancement includes detecting one or more interfering signals at at least one of the one or more probe-in-space antenna elements.

15. The backhaul radio of claim 14, further comprising:

a radio resource controller, wherein the radio resource controller is capable of at least one of i) changing or causing to be changed any attribute of the frequency selective receive path channel multiplexer, ii) changing or causing to be changed, with respect to antenna elements that are couplable to more than one of the plurality of receive RF chains, at least one coupling between any of the plurality of directive gain antenna elements or the one or more probe-in-space antenna elements and any of the plurality of receive RF chains, or iii) changing or causing to be changed at least one of an RF carrier frequency or a channel bandwidth for at least one of the plurality of receive RF chains.

16. The backhaul radio of claim 14 wherein at least one of the one or more probe-in-space antenna elements can be utilized for Dynamic Frequency Selection (DFS) that includes detection of radar systems.

17. The backhaul radio of claim 14 wherein the backhaul radio is capable of transmitting a control frame to a one or more second backhaul radios requesting a change in at least one of an RF carrier frequency or a channel bandwidth in a transmitter of at least one of the one or more second backhaul radios prior to the changing of at least one of an RF carrier frequency or a channel bandwidth in at least one of the plurality of receive RF chains.

18. The backhaul radio of claim 14 wherein said performance enhancement includes one or more of a reduced interference level within one or more of the receive symbol streams, an increased data throughput rate, an improved link diversity, an increased channel efficiency, or an increased signal to interference and noise ratio (SINR).

19. The backhaul radio of claim 14 wherein the one or more probe-in-space antenna elements individually or collectively provides for a substantially non-overlapping azimuthal coverage pattern of approximately 360 degrees.

20. The backhaul radio of claim 14 wherein at least one of the one or more probe-in-space antenna elements provides for an azimuthal coverage pattern of at least 180 degrees.

21. The backhaul radio of claim 14 wherein none of the one or more probe-in-space antenna elements can be utilized for transmission.

22. The backhaul radio of claim 14 wherein the antenna array further comprises one or more selectable RF connections that selectively couple certain of the plurality of directive gain antenna elements to certain of the plurality of receive RF chains and wherein the number of directive gain antenna elements that can be selectively coupled to receive RF chains exceeds the number of receive RF chains that can accept receive RF signals from the one or more selectable RF connections.

23. The backhaul radio of claim 22, further comprising:

a radio resource controller, wherein the radio resource controller sets or causes to be set the specific selective couplings for the one or more selectable RF connections.

24. A backhaul radio comprising:

one or more demodulator cores, wherein each demodulator core is capable of demodulating one or more of a plurality of receive symbol streams to produce one or more receive data interface streams;

a plurality of receive radio frequency (RF) chains, wherein each receive RF chain is capable of converting from one of a plurality of receive RF signals to a respective one of a plurality of receive chain output signals;

a frequency selective receive path channel multiplexer, interposed between the one or more demodulator cores and at least two of the plurality of receive RF chains, wherein the frequency selective receive path channel multiplexer is capable of generating the plurality of receive symbol streams from at least two of the plurality of receive chain output signals provided by said at least two of the plurality of receive RF chains; and

an antenna array comprising;

a plurality of directive gain antenna elements, wherein at least two of the plurality of directive gain antenna elements are each couplable or coupled to at least one of the plurality of receive RF chains coupled to the frequency selective receive path channel multiplexer, thereby producing one or more first respective receive chain output signals; and

one or more probe-in-space antenna elements, wherein at least one of the one or more probe-in-space antenna elements has a larger azimuthal coverage pattern than any of said at least two of the plurality of directive gain antenna elements, and wherein said at least one of the one or more probe-in-space antenna elements is couplable or coupled to at least one of the plurality of receive RF chains coupled to the frequency selective receive path channel multiplexer, thereby producing one or more second respective receive chain output signals;

wherein the backhaul radio is capable of combining the one or more first respective receive chain output signals with the one or more second respective receive chain output signals for a performance enhancement.

25. The backhaul radio of claim 24 wherein the frequency selective receive path channel multiplexer is capable of performing said combining.

26. The backhaul radio of claim 25 wherein the frequency selective receive path channel multiplexer is capable of performing said combining with an MMSE combiner.

27. The backhaul radio of claim 24 wherein said performance enhancement includes one or more of a reduced interference level within one or more of the receive symbol streams, an increased data throughput rate, an improved link diversity, an increased channel efficiency, or an increased signal to interference and noise ratio (SINR).

28. The backhaul radio of claim 24 wherein said performance enhancement includes at least a reduced interference level within one or more of the receive symbol streams.

29. The backhaul radio of claim 24 wherein at least one of the one or more probe-in-space antenna elements can be utilized for Dynamic Frequency Selection (DFS).

30. The backhaul radio of claim 29 wherein at least one of the one or more probe-in-space antenna elements can be utilized both for said Dynamic Frequency Selection (DFS) and for said performance enhancement.