The disclosed subject matter relates to a cognitive radio (CR) receiver for precision navigation and timing (“PNT”) applications and a CR transmitter for PNT applications. Particularly, the present disclosed subject matter is directed to a CR transceiver system of a chip.
PNT needs for both military and civilian applications are primarily enabled by GPS. While GPS can provide navigational accuracy down to a few meters, its accuracy degrades in a multipath environment, and various DoD applications involving drones and mobile platforms require navigational accuracy down to centimeters. Further, GPS signal is weak at the receiver and its carrier frequency is known, making it prone to jamming and spoofing attacks, which can disrupt the GPS based industry and pose a risk to our critical infrastructure. Critical civilian and military applications require precise navigational capabilities in a GPS-denied environment.
There thus remains a need for an efficient and economic method and system for a CR transceiver system on a chip.
The purpose and advantages of the disclosed subject matter will be set forth in and apparent from the description that follows, as well as will be learned by practice of the disclosed subject matter. Additional advantages of the disclosed subject matter will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the disclosed subject matter, as embodied and broadly described, the disclosed subject matter includes a cognitive radio (CR) based transceiver system, which may be on a chip, the system including a receiver comprising a plurality of active resonators, wherein the receiver is configured to sense a predetermined frequency band for a CR signal, wherein the CR signal includes phase noise, a transmitter configured to select a channel for CR signal transmission based on the predetermined frequency band, and generate a carrier frequency for the selected channel and a trained machine learning model configured to correct the phase noise included in the CR signal.
The disclosed subject matter also includes a cognitive radio (CR) receiver, the receiver including a low noise amplifier (LNA) electrically coupled in parallel with both an automatic gain control (AGC) and a received signal strength indicator (RSSI) circuit, wherein the RSSI circuit comprises a plurality of limiting amplifiers, a plurality of active resonators electrically coupled in series to an output of the LNA, a plurality of rectifiers electrically coupled in series to the plurality of active resonators, summation circuitry, electrically coupled in series to the plurality of rectifiers, and a trained machine learning model electrically coupled in series to the summation circuitry, wherein the receiver is configured to sense a predetermined frequency band for a CR signal, wherein the summation circuitry is configured to sum outputs of the plurality of rectifiers and to provide the summed outputs to the trained machine learning model, and wherein the trained machine learning model is configured to correct phase noise included in a CR signal.
The disclosed subject matter also includes a cognitive radio (CR) transmitter, the transmitter including an oscillator, a modulator, a power amplifier (PA) and an antenna, wherein the oscillator, the modulator, the PA, and the antenna are electrically coupled in series, and wherein the transmitter is configured to: select a channel for CR signal transmission based on a predetermined frequency band and generate a carrier frequency for the selected channel.
The discloses subject matter also includes an active resonator, the resonator including a transconductance stage followed by a common-source stage used in a negative feedback, wherein the transconductance stage corresponds to a transconductance value, the transconductance stage and the common-source stage correspond to an output resistance value, and the active resonator is associated with a quality factor, a plurality of output capacitors electronically coupled to the transconductance stage and the common-source stage and a detuning resistor electronically coupled to the transconductance stage and the common-source stage, wherein the detuning resistor is configured to control the quality factor, wherein the active resonator is configured to have a programmable resonant frequency.
The foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the disclosed subject matter claimed.
The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the method and system of the disclosed subject matter. Together with the description, the drawings serve to explain the principles of the disclosed subject matter.
A detailed description of various aspects, features, and embodiments of the subject matter described herein is provided with reference to the accompanying drawings, which are briefly described below. The drawings are illustrative and are not necessarily drawn to scale, with some components and features being exaggerated for clarity. The drawings illustrate various aspects and features of the present subject matter and may illustrate one or more embodiment(s) or example(s) of the present subject matter in whole or in part.
Reference will now be made in detail to exemplary embodiments of the disclosed subject matter, an example of which is illustrated in the accompanying drawings. The method and corresponding steps of the disclosed subject matter will be described in conjunction with the detailed description of the system.
The methods and systems presented herein may be used for a CR transmitter and CR receiver configured to PNT applications. The disclosed subject matter is particularly suited for a CR based transceiver system on a chip. For purpose of explanation and illustration, and not limitation, an exemplary embodiment of the system in accordance with the disclosed subject matter is shown in
As shown in
Receiver 104 includes a plurality of active resonators electrically coupled in series to an output of the LNA 108. In various embodiments, each active resonator 120 of the plurality of active resonators 120 includes a programmable resonant frequency, and wherein each active resonator 20 of the plurality of active resonators 120 is associated with a quality factor. Receiver 104 includes a plurality of rectifiers 124 electrically coupled in series to the plurality of active resonators 120. Receiver 104 includes summation circuitry 128, electrically coupled in series to the plurality of rectifiers 124.
Receiver 104 includes a trained machine learning model 132 electrically coupled in series to the summation circuitry, 128 wherein the receiver 104 is configured to sense a predetermined frequency band for a CR signal, wherein the summation circuitry 128 is configured to sum outputs of the plurality of rectifiers 124 and to provide the summed outputs to the trained machine learning model 12. In various embodiments, the trained machine learning model 132 is configured to correct phase noise included in a CR signal.
Receiver 104 may include a low noise amplifier (LNA) 108 electrically coupled in parallel with both an automatic gain control (AGC) 112 and a received signal strength indicator (RSSI) 116 circuit, wherein the RSSI 116 circuit comprises a plurality of limiting amplifiers. A wide-band low-noise amplifier (LNA) 108 circuit may be used to amplify the RF signal. A parallel AGC 112 using receiver RSSI (RSS-R) is used to prevent the receiver from saturating. The LNA 108 output is fed to active resonators operating differentially as discussed herein. In various embodiments, the receiver further comprises a plurality of rectifiers electrically coupled in series to the plurality of active resonators. The output of the both resonators are fed to rectifiers to demodulate the signal. The rectifier outputs are then summed together to remove out of band and adjacent channel interferers. Finally, the received signal will still suffer from fading and multi-path effects which may be recovered using machine-learning based phase noise correction scheme.
In various embodiments, the RSSI 116 circuit is configured to determine the power level of the CR signal. In various embodiments, the RSSI 116 circuit is configured to control a gain of the LNA 108, wherein the RSSI 116 circuit is further configured to prevent the saturation of the output in a received path for the AGC 112. In various embodiments, the RSSI 116 circuit is configured to continuously detect instability in the CR signal.
Conventional resistive feedback based LNA 108, which can provide high gain with low noise may be used in this project. Some of these techniques involving additional noise cancelling method and multi-stage design with input capacitance cancellation technique can be leveraged in the proposed CR architecture. The resistive feedback base LNA architecture with an RSSI-R based AGC scheme may be utilized.
In various embodiments, receiver 104 includes a plurality of active resonators 120 electrically coupled in series to an output of the LNA. A schematic circuit diagram of an active resonator 120 is shown in
In various embodiments, the programmable resonant frequencies of the plurality of active resonators 120 are the same. In various embodiments, the quality factor associated with each active resonator 120 of the plurality of active resonators is different to the quality factors associated with each of the other active resonators 120 of the plurality of resonators. The use of active resonator 120 shows an ability to sense available RF bands for cognitive communication. However, the Q of the proposed on-chip resonator is still not very high. It can sense RF-media over a wide-band. In cognitive communication application however, such broad RF bands may be completely empty as studies show. However, a strong out of band adjacent blocker can make a wide spectrum unavailable. This has been a design concern in conventional RF receivers. Several blocker tolerant architectures have been proposed in the literature, including mixer first architecture. However, these blockers can only operate at known frequencies, whereas in cognitive communication blockers should operate across a wide frequency.
Referring now to
A narrow channel sensing can be achieved at 12 GHz. To sense the availability of communication channels across a wide band, the value of gm can be swept by changing IB to cover a wide range of frequency around 12 GHz (such as the range in
Referring now to
In various embodiments, cognitive radio (CR) transmitter 1300 for precision navigation and timing (PNT) applications includes an oscillator, wherein the oscillator comprises at least one active resonator 120 electrically coupled in parallel with a high-bandwidth inverting amplifier. The transmitter 1300 includes a modulator 1304, a power amplifier (PA) 1308 and an antenna 1312. In various embodiments, the oscillator, modulator 1304, PA 1308 and antenna 1312 are electrically coupled in series, wherein the transmitter 1300 is configured to select a channel for CR signal transmission based on a predetermined frequency band and generate a carrier frequency for the selected channel.
Once the channels are known, they can be utilized for communication, which requires the generation of carrier frequency for the selected channel. In various embodiments, active resonator 120 generates the carrier frequency. In various embodiments, the oscillator may include at least one active resonator 120 electrically coupled in parallel with a high-bandwidth inverting amplifier. In this case, the resonator is connected across a high-bandwidth inverting amplifier as shown in
In various embodiments, system 100 includes a trained machine learning model 132 configured to correct the phase noise included in the CR signal. In various embodiments, the receiver 104 further comprises summation circuitry, electrically coupled in series to the plurality of rectifiers, and configured to sum outputs of the plurality of rectifiers, and to provide the summed outputs to the trained machine learning model. In various embodiments, the trained machine learning model is trained with a plurality of samples of an envelope of a received RF signal. In various embodiment, the trained machine learning model comprises a timing error function that includes each of the plurality of samples of the envelope of the received RF signal multiplied by a weight associated with that sample.
In the proposed OOK communication, symbol distortion will occur due to fading caused by in-channel multi-path propagation or shadowing effects. The arrival of RF signal through multiple paths at different amplitude and at different time will result into phase offsets in the symbol causing a timing inaccuracy for two-way accurate time-transfer. Fading is one of the dominant sources of error for PNT application. A conventional approach to eliminate fading includes time domain based least square method and frequency domain based inverse correlation method but this can take a long time to predict the error. In various embodiments, ML based phase noise correction scheme 132 for the received symbol may be configured to produce a fast error resolution scheme.
In various embodiments, training data may be collected from any location and stored in a datastore. In various embodiments, data are provided from sensors, and/or the datastore to a machine learning system. In various embodiments, data may be provided to the learning system in real time. In various embodiments, by receiving data live from the user, learning system provides high level analysis that provides adjustment and adaptation of a environment, through changes in the various parameters according to the recorded data.
In some embodiments, a feature vector is provided to the learning system. Based on the input features, the learning system generates one or more outputs. In some embodiments, the output of the learning system is a feature vector.
In some embodiments, the learning system comprises a SVM. In other embodiments, the learning system comprises an artificial neural network. In some embodiments, the learning system is pre-trained using training data. In some embodiments training data is retrospective data. In some embodiments, the retrospective data is stored in a data store. In some embodiments, the learning system may be additionally trained through manual curation of previously generated outputs.
In some embodiments, the learning system is a trained classifier. In some embodiments, the trained classifier is a random decision forest. However, it will be appreciated that a variety of other classifiers are suitable for use according to the present disclosure, including linear classifiers, support vector machines (SVM), or neural networks such as recurrent neural networks (RNN).
Suitable artificial neural networks include but are not limited to a feedforward neural network, a radial basis function network, a self-organizing map, learning vector quantization, a recurrent neural network, a Hopfield network, a Boltzmann machine, an echo state network, long short term memory, a bi-directional recurrent neural network, a hierarchical recurrent neural network, a stochastic neural network, a modular neural network, an associative neural network, a deep neural network, a deep belief network, a convolutional neural networks, a convolutional deep belief network, a large memory storage and retrieval neural network, a deep Boltzmann machine, a deep stacking network, a tensor deep stacking network, a spike and slab restricted Boltzmann machine, a compound hierarchical-deep model, a deep coding network, a multilayer kernel machine, or a deep Q-network.
Precision Timer, Time-Transfer and Synchronization: in various embodiments, both nodes, in a two-way time transfer scheme, will maintain a precision clock whose relative timing error with respect to each other is very low (in ppb) using TCXO or chip-scale atomic dock (C SAC). For time transfer, each node can send a symbol at the end of every second. Each node can wake up at 2 μs before the n-th second and identify available communication channel (within 11.6) and tune the transmitter and receiver circuit. At the end of a second, each node can send their timing symbol using a given CR channel. The delay of arrival of the symbol and the drift between two clocks can be used to calculate the pseudo-range using TDoA technique for PNT applications.
Chip Design and Power Consumption: The complete CR system along with the ML based phase noise correction scheme will be integrated on a chip. The CR system can sense the channel in 1 μs and be ready for communication in the next μs, while conventional radio takes 10 s of ms to startup. It is easier to duty-cycle the proposed CR system. A target of 20 mW power consumption for the CR system when active with active time being low (<5 μs) for time transfer. Assuming time transfer every second, average power consumption can be as low as 100 nW. The proposed work will have a major impact on the Swap-C of existing CR systems which are heavy back-pack system.
Although this disclosure includes a detailed description of a chip, implementation of the teachings recited herein are not limited to any one computing environment. Rather, embodiments of the present disclosure are capable of being implemented in conjunction with any other type of computing environment or cloud computing environment now known or later developed.
Referring now to
In computing node 10 there is a computer system/server 12, which is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with computer system/server 12 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems or devices, and the like.
Computer system/server 12 may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Computer system/server 12 may be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices.
As shown in
Bus 18 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, Peripheral Component Interconnect (PCI) bus, Peripheral Component Interconnect Express (PCIe), and Advanced Microcontroller Bus Architecture (AMBA).
Computer system/server 12 typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system/server 12, and it includes both volatile and non-volatile media, removable and non-removable media.
System memory 28 can include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and/or cache memory 32. Computer system/server 12 may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system 34 can be provided for reading from and writing to a non-removable, non-volatile magnetic media (not shown and typically called a “hard drive”). Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM or other optical media can be provided. In such instances, each can be connected to bus 18 by one or more data media interfaces. As will be further depicted and described below, memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the disclosure.
Program/utility 40, having a set (at least one) of program modules 42, may be stored in memory 28 by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules 42 generally carry out the functions and/or methodologies of embodiments as described herein.
Computer system/server 12 may also communicate with one or more external devices 14 such as a keyboard, a pointing device, a display 24, etc.; one or more devices that enable a user to interact with computer system/server 12; and/or any devices (e.g., network card, modem, etc.) that enable computer system/server 12 to communicate with one or more other computing devices. Computer system/server 12 may also communicate with an antenna as described herein, such as receiver 104, transmitter 1300, and specifically antenna 1312, in embodiments. Such communication can occur via Input/Output (I/O) interfaces 22. Still yet, computer system/server 12 can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet) via network adapter 20. As depicted, network adapter 20 communicates with the other components of computer system/server 12 via bus 18. It should be understood that although not shown, other hardware and/or software components could be used in conjunction with computer system/server 12. Examples, include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.
The present disclosure may be embodied as a system, a method, and/or a computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present disclosure.
The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.
Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.
Computer readable program instructions for carrying out operations of the present disclosure may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present disclosure.
Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.
These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.
The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.
The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.
While the disclosed subject matter is described herein in terms of certain preferred embodiments, those skilled in the art will recognize that various modifications and improvements may be made to the disclosed subject matter without departing from the scope thereof. Moreover, although individual features of one embodiment of the disclosed subject matter may be discussed herein or shown in the drawings of the one embodiment and not in other embodiments, it should be apparent that individual features of one embodiment may be combined with one or more features of another embodiment or features from a plurality of embodiments.
In addition to the specific embodiments claimed below, the disclosed subject matter is also directed to other embodiments having any other possible combination of the dependent features claimed below and those disclosed above. As such, the particular features presented in the dependent claims and disclosed above can be combined with each other in other manners within the scope of the disclosed subject matter such that the disclosed subject matter should be recognized as also specifically directed to other embodiments having any other possible combinations. Thus, the foregoing description of specific embodiments of the disclosed subject matter has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosed subject matter to those embodiments disclosed.
It will be apparent to those skilled in the art that various modifications and variations can be made in the method and system of the disclosed subject matter without departing from the spirit or scope of the disclosed subject matter. Thus, it is intended that the disclosed subject matter include modifications and variations that are within the scope of the appended claims and their equivalents.
This application claims the benefit of priority to U.S. Provisional Application No. 63/388,364, filed Jul. 12, 2022.
Number | Date | Country | |
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63388364 | Jul 2022 | US |