The present disclosure provides radio-frequency (RF) systems that can detect the presence of RF signals received by the system, as well as determine characteristics such as the operating frequency of RF signals, the type of RF source that transmitted each RF signal, and/or the location of each RF source with high precision and sensitivity while using low cost, scalable electronics that are versatile enough for deployment in a variety of environments. Such systems can employ a network of RF sensors that can coordinate in response to communication with a computer to perform any such detection and/or determination using trained models executed onboard the RF sensors and/or the computer. RF signals may have unique characteristics when received at one or more RF sensors that may be detected using trained models described herein, even in high noise or non-line of sight (LOS) environments and with low cost, low resolution RF receiver hardware.

The systems and methods described relate to the concept that smart devices can be used to 1) sense various types of phenomena like sound, blue light exposure, RF and microwave radiation, and 2) in real-time analyze, report and/or control outputs (e.g., displays or speakers). The systems are configurable and use standard computing devices, such as wearable electronics, tablet computers, and mobile phones to measure various frequency bands across multiple points, allowing a single user to visualize and/or adjust environmental conditions.

A software-defined radio system may include a radio frequency front end connected to a high performance computing processor comprised of a central processing unit (CPU), a graphics processing unit (GPU), and a shared memory between the CPU and GPU. The software-defined radio system may incorporate a signal processing unit between the radio frequency front end and the high performance computing processor. Additionally, the software-defined radio system may be configured to create a ring buffer in a shared memory between the CPU and GPU and directly store digital signal data in the ring buffer. The software-defined radio system may be used to implement and train machine learning algorithms and transmit digital signals.

A high speed split receiver interface system for sensing a series of external signals, the system including: a series of remote radio head units for receiving a sensed signal in an analog electric form, each of the remote radio head units converting their sensed signal to a corresponding digital electrical form and then to a corresponding optical data form for dispatch over an optical data interconnection; at least one optical interconnect interconnecting each remote radio head unit with a baseband unit; a first baseband unit interconnecting the series of remote head units corresponding optical interconnects, and including a converter for conversion of the received optical signals to corresponding electrical digital form and down sampling the optical signals to corresponding down sampled signals, a memory store for storing the down sampled signals, and an external network interface for transmission of the saved signals to an external device.

A security analysis method for a control plane and a system therefor are disclosed. The method includes generating a test case for a security property unsuitable for a control plane operation, transmitting the generated test case to target equipment and receiving a response of the control plane for the test case from the target equipment, and diagnosing security for the security property of the target equipment by analyzing the received response. The generating includes generating the test case for the security property by modulating a value of a specific field in a control plane protocol header into a value unsuitable for an operation on standards.

A calibration system including a signal generator device, at least one calibration receiver and a processing circuit is described. The signal generator device has a signal generation circuit configured to generate a signal, at least one signal path terminating at a signal output port of the signal generator device, and at least one tap provided in the signal path. The at least one calibration receiver is connected with the at least one tap in the signal path. The at least one calibration receiver is connected with the processing circuit. The processing circuit is configured to receive measurement results obtained by the at least one calibration receiver and to analyze the measurement results received, thereby determining analysis results.

A user device communicates in a wireless network by encoding a set of data symbols with a set of complex-valued codes to produce a set of subcarrier values. The subcarrier values are modulated onto a set of Orthogonal Frequency Division Multiplexing (OFDM) subcarriers assigned to the user device to produce a time-domain waveform that comprises a superposition of modulated subcarriers, and the time-domain waveform is transmitted in the wireless network. The set of subcarrier values comprises a first polyphase code that encodes a first of the set of data symbols and at least a second polyphase code that encodes at least a second of the set of data symbols. The first polyphase code causes constructive and destructive interference between the modulated subcarriers to produce a first periodic pulse waveform having a peak value centered at a first time in an OFDM symbol interval, and the second polyphase code causes constructive and destructive interference between the modulated subcarriers to produce a second periodic pulse waveform having a peak value centered at a second time in the OFDM symbol interval, wherein the second time is different from the first time.

A system for monitoring cellular communications including a passive sensor device, processors, and memory devices. The memory devices having instructions that cause the processors to identify active downlink channels using a first radio to monitor each channel in a cellular spectrum and store downlink channel information, including configuration data, for each of the identified active downlink channels. The processors identify active uplink channels using a second radio to monitor each channel in the cellular spectrum and store uplink channel information for each of the identified active uplink channels. The processors correlate one of the active uplink channels with a corresponding active downlink channel and tune a third radio to the active uplink channel using the configuration data for the corresponding active downlink channel. The processors also tune a fourth radio to the active downlink channel corresponding to the at least one active uplink channel using the corresponding configuration data.

Disclosed in some examples are systems, methods, devices, and machine-readable mediums for improved communications between a software-defined radio front-end device and a network-based computing device. Rather than packetize samples together, same bit positions from multiple ADC samples may be packetized together. If a Quality of Service (QoS) metric of the network connection between the RF front-end device and the network-based processing computing drops below a threshold, the RF front-end device may prioritize sending packets with the more significant bits over packets with less significant bits. In other examples, the RF front-end device may prioritize samples corresponding to certain data types over other data types.

A flexible channel bandwidth for mobile radio communications is provided by provisioning a set of Orthogonal Frequency Division Multiplexing (OFDM) subcarriers for mobile radio communications; encoding data symbols with polyphase codes derived from a discrete Fourier transform to produce encoded data symbols; and modulating the encoded data symbols onto the OFDM subcarriers to produce a superposition signal that resembles a single-carrier signal and has one of a plurality of different symbol durations. The provisioning comprises selecting one of a plurality of different selectable subcarrier spacings, to provide for the one of the plurality of different symbol durations.