System for suppressing radio interference through active filtering and modulation detection

Abstract

A method for suppressing radio interference by active filtering and modulation detection includes receiving a signal at a radio device and digitizing the signal to generate a digitized signal. The method further includes processing the digitized signal to extract a carrier frequency of the digitized signal and one or more signal characteristics of the digitized signal. Based on the carrier frequency of the digitized signal and the one or more signal characteristics of the digitized signal, the method further includes determining a linear offset of the one or more signal characteristics of the digitized signal relative to the carrier frequency of the digitized signal using a symmetric filtering model, and filtering the signal using a filter.

Description

Technical Field

[0001] The present disclosure generally relates to radio equipment. In particular, the present disclosure relates to actively filtering interference from noise sources in an electric vehicle propulsion system. Background Art

[0002] The information provided in this section is for the purpose of presenting the background of the present disclosure in general. To the extent described in this section, the work of the presently named inventors, as well as aspects that may not qualify as prior art at the time of filing, are neither expressly nor implicitly admitted as prior art with respect to the present disclosure.

[0003] For example, in a hybrid vehicle or an electric vehicle, the vehicle propulsion system employs pulse-width modulation switch control. These control frequencies are typically in the kilohertz (kHz) range (e.g., less than 10 kHz) and cause harmonic interference in the amplitude modulation (AM) frequency band received by the vehicle radio equipment. Specifically, the AM frequency band extends from approximately 525 kHz to 1710 kHz in 10 kHz increments, where a switch control frequency operating at 6 kHz may cause interference at 600 kHz (i.e., the hundredth harmonic), 900 kHz (i.e., the 150th harmonic of the control frequency), etc. Although attempts have been made previously to filter the control frequencies of the vehicle propulsion system, due to the multi-layer communication between the vehicle radio equipment, filters, communication buses, and vehicle network, these systems may include additional processing. Summary of the Invention

[0004] One aspect of the present disclosure provides a computer-implemented method for suppressing radio interference through active filtering and modulation detection. When executed on data processing hardware, the method causes the data processing hardware to perform operations including receiving a signal at a radio device and digitizing the signal to generate a digitized signal. The operations further include processing the digitized signal to extract the carrier frequency of the digitized signal and one or more signal characteristics of the digitized signal. Based on the carrier frequency of the digitized signal and one or more signal characteristics of the digitized signal, the operations further include determining a linear offset of one or more signal characteristics of the digitized signal relative to the carrier frequency of the digitized signal using a symmetric filtering model, and filtering the signal using a filter.

[0005] Embodiments of the present disclosure may include one or more of the following optional features. In some embodiments, the signal includes a pulse-width modulation switch control frequency. In some examples, the radio device is disposed within a vehicle. In some embodiments, the symmetric filtering model applies a filtering algorithm to one or more signal characteristics of the digitized signal. In these examples, the filtering algorithm may include digital signal processing, and the filtering algorithm identifies patterns of the digitized signal in the frequency domain.

[0006] In some embodiments, filtering a signal using a filter includes applying a selective digital notch filter to the digitized signal. In some examples, one or more signal characteristics of the digitized signal are in the frequency domain. In some embodiments, the carrier frequency of the digitized signal is 10 kilohertz.

[0007] In some examples, the operations further include receiving a subsequent signal at the radio device and digitizing the subsequent signal to generate a digitized subsequent signal. Here, the operations further include processing the digitized subsequent signal to extract the carrier frequency of the digitized subsequent signal and one or more signal characteristics of the digitized subsequent signal. Based on the carrier frequency of the digitized subsequent signal and one or more signal characteristics of the digitized subsequent signal, the operations further include using a symmetric filtering model to determine that one or more signal characteristics of the digitized subsequent signal are symmetrically offset relative to the carrier frequency of the digitized subsequent signal, and allowing the subsequent signal. In some embodiments, the subsequent signal includes an amplitude correction signal.

[0008] Another aspect of the present disclosure provides a system for suppressing radio interference through active filtering and modulation detection. The system includes data processing hardware and memory hardware communicatively coupled to the data processing hardware. The memory hardware stores instructions that, when executed by the data processing hardware, cause the data processing hardware to perform operations including receiving a signal at the radio device and digitizing the signal to generate a digitized signal. The operations further include processing the digitized signal to extract the carrier frequency of the digitized signal and one or more signal characteristics of the digitized signal. Based on the carrier frequency of the digitized signal and one or more signal characteristics of the digitized signal, the operations further include using a symmetric filtering model to determine that one or more signal characteristics of the digitized signal are linearly offset relative to the carrier frequency of the digitized signal, and filtering the signal using a filter.

[0009] This aspect may include one or more of the following optional features. In some embodiments, the signal includes a pulse width modulation switching control frequency. In some examples, the radio device is disposed within a vehicle. In some embodiments, the symmetric filtering model applies a filtering algorithm to one or more signal characteristics of the digitized signal. In these examples, the filtering algorithm may include digital signal processing, and the filtering algorithm identifies patterns of the digitized signal in the frequency domain.

[0010] In some embodiments, filtering a signal using a filter includes applying a selective digital notch filter to the digitized signal. In some examples, one or more signal characteristics of the digitized signal are in the frequency domain. In some embodiments, the carrier frequency of the digitized signal is 10 kilohertz.

[0011] In some examples, the operations further include receiving a subsequent signal at the radio device and digitizing the subsequent signal to generate a digitized subsequent signal. Here, the operations further include processing the digitized subsequent signal to extract the carrier frequency of the digitized subsequent signal and one or more signal characteristics of the digitized subsequent signal. Based on the carrier frequency of the digitized subsequent signal and the one or more signal characteristics of the digitized subsequent signal, the operations further include determining that one or more signal characteristics of the digitized subsequent signal are symmetrically offset relative to the carrier frequency of the digitized subsequent signal using a symmetric filtering model, and allowing the subsequent signal. In some embodiments, the subsequent signal includes an amplitude correction signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings described herein are for illustrative purposes only of selected configurations and are not intended to limit the scope of the present disclosure.

[0013] Figure 1 is a schematic diagram of an example system for suppressing radio interference through active filtering and modulation detection.

[0014] Figure 2 is Figure 1 a schematic diagram of example components of a system of

[0015] Figure 3A and Figure 3B is a schematic diagram of a digitized signal.

[0016] Figure 4 is a flowchart of an example operational arrangement of a method for suppressing radio interference via active filtering and modulation detection.

[0017] In all the drawings, corresponding reference numerals represent corresponding parts. DETAILED DESCRIPTION

[0018] Example configurations will now be described more fully with reference to the accompanying drawings. Example configurations are provided so that this disclosure will be thorough and will fully convey the scope of the disclosure to those of ordinary skill in the art. Specific details, such as examples of specific components, devices, and methods, are set forth to provide a thorough understanding of the configurations of the present disclosure. It will be apparent to those of ordinary skill in the art that specific details need not be employed, that example configurations may be embodied in many different forms, and that neither the specific details nor the example configurations should be construed as limiting the scope of the disclosure.

[0019] The terms used herein are for the purpose of describing particular exemplary configurations only and are not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may also be intended to include the plural forms, unless the context clearly indicates otherwise. The terms "comprising", "including", "having" and "containing" are inclusive and thus specify the presence of stated features, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components and / or groups thereof. The method steps, processes and operations described herein should not be construed as necessarily requiring them to be performed in the particular order discussed or illustrated, unless specifically identified as an order of performance. Additional or alternative steps may be employed.

[0020] When an element or layer is referred to as being "on", "engaged to", "connected to", "attached to" or "coupled to" another element or layer, it can be directly on, engaged, connected, attached or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on", "directly engaged to", "directly connected to", "directly attached to" or "directly coupled to" another element or layer, intervening elements or layers may not be present. Other words used to describe the relationship between elements should be interpreted in a like manner (e.g., "between" versus "directly between", "adjacent" versus "directly adjacent", etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0021] The terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and / or sections. These elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another. Terms such as "first", "second" and other numerical terms do not imply an order or sequence unless the context clearly indicates otherwise. Thus, a first element, component, region, layer or section discussed below may be referred to as a second element, component, region, layer or section without departing from the teachings of the exemplary configuration.

[0022] In this application, including the definitions below, the term module may be replaced with the term circuit. The term "module" may refer to, or include as part of, an application specific integrated circuit (ASIC); digital, analog or mixed analog / digital discrete circuits; digital, analog or mixed analog / digital integrated circuits; combinational logic circuits; field programmable gate arrays (FPGA); processors (shared, dedicated or grouped) that execute code; memory (shared, dedicated or grouped) that stores code executed by the processor; other suitable hardware components that provide the stated functionality; or some or all of the above combinations, such as in a system-on-chip.

[0023] The term codes used above may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, and / or objects. The term shared processor includes a single processor that executes portions or all of the codes from multiple modules. The term grouped processors includes a processor that, in combination with additional processors, executes some or all of the codes from one or more modules. The term shared memory includes a single memory that stores some or all of the codes from multiple modules. The term grouped memory includes a memory that, in combination with additional memories, stores some or all of the codes from one or more modules. The term memory may be a subset of the term computer-readable medium. The term computer-readable medium does not include transient electrical signals and electromagnetic signals propagated through the medium and may thus be considered tangible non-transitory memory. Non-limiting examples of non-transitory memory include tangible computer-readable media including non-volatile memory, magnetic memory, and optical memory.

[0024] The apparatus and methods described in this application may be implemented in part or in whole by one or more computer programs executed by one or more processors. The computer programs include processor-executable instructions stored on at least one non-transitory tangible computer-readable medium. The computer programs may also include and / or rely on stored data.

[0025] A software application (i.e., software resource) may refer to computer software that causes a computing device to perform tasks. In some examples, a software application may be referred to as an “application program,” “app,” or “program.” Example applications include, but are not limited to, system diagnostic applications, system management applications, system maintenance applications, word processing applications, spreadsheet applications, messaging applications, media streaming applications, social networking applications, and gaming applications.

[0026] Non-transitory memory may be a physical device for temporarily or permanently storing programs (e.g., sequences of instructions) or data (e.g., program state information) for use by a computing device. Non-transitory memory may be volatile and / or non-volatile addressable semiconductor memory. Examples of non-volatile memory include, but are not limited to, flash memory and read-only memory (ROM) / programmable read-only memory (PROM) / erasable programmable read-only memory (EPROM) / electrically erasable programmable read-only memory (EEPROM) (e.g., typically used for firmware, such as a boot program). Examples of volatile memory include, but are not limited to, random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), phase change memory (PCM), and magnetic disks or tapes.

[0027] These computer programs (also known as programs, software, software applications or code) include machine instructions for a programmable processor and can be implemented in high-level procedural and / or object-oriented programming languages and / or assembly / machine languages. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, non-transitory computer-readable medium, device, and / or apparatus (e.g., a magnetic disk, an optical disk, a memory, a programmable logic device (PLD)) that provides machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal that provides machine instructions and / or data to a programmable processor.

[0028] The various implementations of the systems and techniques described herein can be implemented in digital electronic and / or optical circuits, integrated circuits, specially designed ASICs (application specific integrated circuits), computer hardware, firmware, software, and / or combinations thereof. These different implementations can include implementations in one or more computer programs executable and / or interpretable on a programmable system including at least one programmable processor, at least one input device, and at least one output device, the programmable processor may be special or general purpose and is coupled to receive data and instructions from, and to send data and instructions to, a storage system.

[0029] The processes and logical flows described in this specification can be performed by one or more programmable processors, also known as data processing hardware, executing one or more computer programs to perform functions by operating on input data and generating output. These processes and logical flows can also be performed by special-purpose logic circuitry, such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). By way of example, processors suitable for executing computer programs include both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more storage devices for storing instructions and data. Generally, a computer will also include or be operatively coupled to one or more mass storage devices for storing data, such as magnetic disks, magneto-optical disks, or optical disks, to receive data from or transfer data to the mass storage device, or both. However, a computer need not have such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and storage devices, including by way of example semiconductor storage devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special-purpose logic circuitry.

[0030] To provide for interaction with a user, one or more aspects of the present disclosure can be implemented on a computer having a display device, such as a CRT (Cathode Ray Tube), LCD (Liquid Crystal Display) monitor, or touch screen, for displaying information to the user, and a keyboard and a pointing device, such as a mouse or a trackball, optional, by which the user can provide input to the computer. Other types of devices can also be used to provide for interaction with the user; for example, feedback provided to the user can be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback; and input received from the user can be in any form, including acoustic, speech, or tactile input. Additionally, the computer can interact with the user by sending documents to and receiving documents from the device used by the user; for example, by sending a web page to a web browser on a client device of the user in response to a request received from the web browser.

[0031] Figure 1 An example system 100 is shown, including a vehicle 10 and / or a remote system 60 in communication with the vehicle 10 via a network 40. The vehicle 10 and / or the remote system 60 includes an active filtering and modulation detection system 204 ( Figure 2) radio device 200, and the active filtering and modulation detection system 204 filters harmonics from noise sources in vehicle 10 that may interfere with the amplitude modulation (AM) radio device. In particular, radio device 200 may receive signal 202 from a desired source (e.g., AM radio signal 202R) and signal 202 from noise generated by components within vehicle 10 and / or the surrounding environment of vehicle 20 (e.g., noise signal 202N). The active filtering and modulation detection system 204 is configured to receive signal 200 and selectively apply filter 240 to noise signal 202N while allowing radio signal 202R.

[0032] In the example shown, the active filtering and modulation detection system 204 is implemented within radio device 200 of vehicle 10. However, the active filtering and modulation detection system 204 may be implemented on other devices (e.g., a computing device in communication with vehicle 10), such as but not limited to smartphones, tablets, smart displays, desktop / laptop computers, smartwatches, smart appliances, headphones, smart glasses / headsets, or vehicle infotainment devices. Vehicle 10 includes data processing hardware 12 and memory hardware 14 that stores instructions that, when executed on data processing hardware 12, cause data processing hardware 14 to perform operations. Remote system 60 (e.g., a server, a cloud computing environment) also includes data processing hardware 62 and memory hardware 64 that stores instructions that, when executed on data processing hardware 62, cause data processing hardware 62 to perform operations. In some examples, the execution of the active filtering and modulation detection system 204 is shared by radio device 200 within vehicle 10 and remote system 60. As described in more detail below with reference to Figure 2 The active filtering and modulation detection system 204, executed on vehicle 10 (e.g., radio device 200) and / or remote system 60, executes a digitization module 210, an extraction module 220, and a symmetric filtering model 230 that selectively applies filter 240 to received signal 202. The active filtering and modulation detection system 204 is configured to receive signal 202 of vehicle 10 (i.e., AM signal 202R, noise signal 202N) and selectively apply filter 240 to signal 202 based on the respective frequency components of received signal 202.

[0033] The radio device 200 of vehicle 10 can be configured to receive and demodulate signals 202, such as AM signal 202R. However, vehicle 10 may also include an electric propulsion system 16 that employs pulse modulation switch control, which generates a pulse-width modulation switch control signal 202N that interferes with the AM signal 202R. These noise signals 202N are typically in the kilohertz (kHz) range (e.g., less than 10 kHz) and cause harmonic interference in the frequency band of the AM signal 202R received by the vehicle radio device 200. Specifically, the frequency band of the AM signal 202R extends from approximately 525 kHz to 1710 kHz in 10 kHz increments, and a switching control frequency operating at 6 kHz may cause the noise signal 202N to interfere at 600 kHz (i.e., the one-hundredth harmonic), 900 kHz (i.e., the one-hundred-and-fiftieth harmonic of the control frequency), etc. By detecting the frequency characteristics of the received signal 202, the active filtering and modulation detection system 204 can selectively apply filters to remove / suppress the noise signal 202N to prevent interference with the AM signal 202R and other desired signals 202R.

[0034] Reference Figure 2 , the vehicle implements an active filtering and modulation detection system 204 that receives the signal 202 as an input and selectively filters the signal 202 based on whether the signal 202 is a radio signal 202R or a noise signal 202N without calculating the frequency and harmonic bands of the noise signal 202N. The active filtering and modulation detection system 204 also includes a digitization module 210, an extraction module 220, and a symmetric filtering model 230 that selectively applies filters 240. The digitization module 210 is configured to receive the signal 202 as an input and digitize the signal 202 to generate a digitized signal 212. The digitization module 210 may include an RF digitizer that is configured to receive the analog signal 202 and convert the signal 202 into an equivalent digital signal for additional processing and storage.

[0035] The extraction module 220 is configured to receive the digitized signal 212 generated / output by the digitization module 210 and process the digitized signal 212 to extract the carrier frequency 222 of the digitized signal 212 and one or more signal characteristics 224 of the digitized signal 212. The extraction module 220 may apply digital signal processing (DSP) techniques to the digitized signal 212 to identify the respective signal characteristics 224 of the received signal 202. Specifically, the respective signal characteristics 224 may include respective frequency components, such as how the frequency of the signal 202 is modulated (i.e., in the frequency domain) as the signal 202 is tracked over time. For example, reference Figure 3A and Figure 3B, the schematic diagrams 300a, 300b show the digital signal 212 in the time-frequency domain (e.g., kHz) while tracking the digital signal 212 over time. Here, the frequency of the digital signal 212 is set on the x-axis, and the y-axis represents the time when the digital signal 212 is tracked / received. With particular reference to Figure 3A , the radio signal 202R (e.g., the AM radio signal 202R) is processed by the extraction module 220. As shown, the extraction module 220 extracts the carrier frequency 222R of the digital radio signal 212R and the signal feature 224R of the digital radio signal 212R. Here, the signal feature 224R symmetrically deviates from the carrier frequency 222R such that the interval changes. For example, the signal feature 224R can deviate from the carrier frequency 222R by + / -1 kHz to + / -1.2 kHz over time.

[0036] Conversely, with reference to Figure 3B , the noise signal 202N (e.g., the noise signal 202N generated by the electric propulsion system 16) is processed by the extraction module 220. Here, the extraction module extracts the carrier frequency 222N of the digital noise signal 212N and the signal feature 224N of the digital noise signal 212N. Here, the signal feature 224N linearly deviates from the carrier frequency 222N. In other words, the signal feature 224 of the digital noise signal 212N maintains a consistent interval around the carrier frequency 222N. For example, the signal feature 224N can deviate from the carrier frequency 222N of the digital noise signal 212N by 10 to 10.2 kHz over time.

[0037] Referring again to Figure 2, the symmetric filter model 230 is configured to receive the carrier frequency 222 and one or more signal features 224 extracted by the extraction module 220, and identify whether one or more signal features 224 are linearly offset or symmetrically offset relative to the carrier frequency 222. The symmetric filter model 230 can apply a filtering algorithm to one or more signal features 224 of the digitized signal 212. For example, the filtering algorithm can employ DSP technology to identify patterns in the digitized signal 212 in the frequency domain and apply a notch filter 240 to remove interference from the noise signal 202N from the radio signal 202R. The patterns in the digitized signal 212 can include the type of change in the signal 202, the spacing of the modulated signal 202, or how the modulated signal 202 moves in the frequency domain. It is noted that when the symmetric filter model 230 determines that one or more signal features 224 of the digitized signal 212 are linearly offset relative to the carrier frequency 222, the symmetric filter model 230 identifies the signal 202 as the noise signal 202N and filters / suppresses the signal 202N using the filter 240. In contrast, when the symmetric filter model 230 determines that one or more signal features 224 of the digitized signal 212 are symmetrically offset relative to the carrier frequency 222, the symmetric filter model 230 identifies the signal 202 as the radio signal 202R and does not filter the signal 202R (i.e., allows the signal 202R to be further processed / played).

[0038] Figure 4 A flowchart including an example operational arrangement of a method 400 for suppressing radio interference in a vehicle 10 through active filtering and modulation. At operation 402, the method 400 includes receiving a signal 202 at a radio device 200. The signal 202 can be an AM radio signal 202R or a noise signal 202N. At operation 404, the method 400 includes digitizing the received signal 202 to generate a digitized signal 212.

[0039] At operation 406, the method 400 further includes processing the digitized signal 212 to extract the carrier frequency 222 of the digitized signal 212 and one or more signal features 224 of the digitized signal 212. Based on the carrier frequency 222 of the digitized signal 212 and one or more signal features 224 of the digitized signal 212, the method 400 further includes determining at operation 408 using the symmetric filter model 230 whether one or more signal features 224 of the digitized signal 212 are linearly shifted relative to the carrier frequency 224 of the digitized signal 212. At operation 410, the method further includes filtering the signal 202 using the filter 240.

[0040] Numerous embodiments have been described. However, it should be understood that various modifications can be made without departing from the spirit and scope of the present disclosure. Accordingly, other embodiments are also within the scope of the following claims.

[0041] For purposes of explanation and description, the foregoing description has been provided. It is not intended to be exhaustive or to limit the disclosure. A single element or feature of a particular configuration is generally not limited to that particular configuration, but, where applicable, is interchangeable and can be used in a selected configuration even if not specifically shown or described. This can also vary in many ways. Such variations should not be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

1. A computer-implemented method that, when executed on data processing hardware, causes the data processing hardware to perform operations including the following: Receiving a signal at a radio device; Digitizing the signal to generate a digitized signal; Processing the digitized signal to extract the carrier frequency of the digitized signal and one or more signal characteristics of the digitized signal; Using a symmetric filtering model to determine a linear shift of one or more signal characteristics of the digitized signal relative to the carrier frequency of the digitized signal based on the carrier frequency of the digitized signal and one or more signal characteristics of the digitized signal; and Filtering the signal using a filter.

2. The method according to claim 1, wherein The signal includes a pulse width modulation switching control frequency.

3. The method according to claim 1, wherein The radio device is disposed within a vehicle.

4. The method according to claim 1, wherein, The symmetric filtering model applies a filtering algorithm to one or more signal characteristics of the digitized signal.

5. The method according to claim 4, wherein, The filtering algorithm includes digital signal processing, and the filtering algorithm identifies patterns of the digitized signal in the frequency domain.

6. The method according to claim 1, wherein, Filtering the signal using a filter includes applying a selective digital notch filter to the digitized signal.

7. The method according to claim 1, wherein, One or more signal characteristics of the digitized signal are in the frequency domain.

8. The method according to claim 1, wherein The carrier frequency of the digitized signal is 10 kilohertz.

9. The method according to claim 1, wherein The operations further include: Receiving a subsequent signal; Digitizing the subsequent signal to generate a digitized subsequent signal; Processing the digitized subsequent signal to extract the carrier frequency of the digitized subsequent signal and one or more signal characteristics of the digitized subsequent signal; Using a symmetric filtering model to determine a symmetric shift of one or more signal characteristics of the digitized subsequent signal relative to the carrier frequency of the digitized subsequent signal based on the carrier frequency of the digitized subsequent signal and one or more signal characteristics of the digitized subsequent signal; and Allowing the subsequent signal.

10. The method according to claim 9, wherein, The subsequent signal includes an amplitude correction signal.

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