Example embodiments relate to methods for distance determination. One embodiment includes a method for determining a distance between a first radio signal transceiver and a second radio signal transceiver. The method includes receiving a first set and a second set of measurement results. The first set is acquired by the first radio signal transceiver based on signals transmitted from the second radio signal transceiver and the second set is acquired by the second radio signal transceiver based on signals transmitted from the first radio signal transceiver. The first set is representable as including, for each of a plurality of frequencies, a measurement pair. The method also includes calculating, for each frequency of the plurality of frequencies, a preliminary estimate of a value proportional to a one-way frequency domain channel response. Additionally, the method includes determining a final estimate of the value proportional to the one-way frequency domain channel response.

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.

Disclosed are a test instrument and testing methods for audibly providing signal metrics (such as signal strength and/or signal quality) of fifth-generation network (5G) beams to assist installation of 5G Customer Premises Equipment (CPE) antenna at a premises. A test instrument may obtain signal metrics and provide audio output based on the signal metrics at various locations of the premises. The audio output may be transmitted to a headphone device worn by a user. In this manner, the user may select an appropriate location on the premises at which to install the 5G CPE antenna via audible queues that are based on the measured signal metric at a given location. The test instrument may provide fine-tuning capabilities by also audibly providing directional information that indicates where the 5G CPE antenna should be pointed or moved to align the 5G CPE antenna to a 5G beam.

A method for reference signal processing is provided. In this example, the method includes receiving, by a UE, a message from a network device, where the message indicates both that a first reference signal is to be transmitted over a first resource and that a second reference signal is to be transmitted over a second resource. The method also includes receiving, by the UE, at least the first reference signal in accordance with capabilities of the UE and the message received from the network device.

A radio communication apparatus according to an exemplary aspect includes: a detection unit configured to detect an object flying in the vicinity of a propagation path of directional radio waves; a distance calculation unit configured to calculate a distance between the propagation path of the radio waves and the object detected by the detection unit; a change amount determination unit configured to determine a change amount of a transmission power value used in performing transmission of the radio waves in accordance with the distance calculated by the distance calculation unit; and a signal control unit configured to control the transmission power value based on the change amount determined by the change amount determination unit. The change amount determination unit adopts a positive value as the change amount when the calculated distance is equal to or smaller than the prescribed distance.

Embodiments of the present disclosure relate to a method and an apparatus for antenna calibration. A method performed by an apparatus for antenna calibration may comprise: inserting a calibration signal to a physical resource block allocated for a traffic signal; and distinguishing the calibration signal from the traffic signal at a calibration receiver for antenna calibration. According to embodiments of the present disclosure, antenna calibration signals and traffic signals may be transmitted simultaneously.

A method of determining reserved tones to be used for reduction of a peak to average power ratio (PAPR) of a signal includes: randomly selecting carrier indices for the reserved tones and generating a kernel signal based on the randomly selected carrier indices; calculating a comparison reference average value of the kernel signal, comparing the calculated comparison reference average value with a prestored comparison reference average value, and preliminarily determining carrier indices of the reserved tones based on the comparison; randomly re-arranging an order of the preliminarily determined carrier indices of the reserved tones; and calculating the comparison reference average value while changing each of the re-arranged indices of the reserved tones, and finally determining carrier indices for which the calculated comparison reference average value becomes the smallest value as carrier indices of the reserved tones.

A method of determining reserved tones to be used for reduction of a peak to average power ratio (PAPR) of a signal includes: randomly selecting carrier indices for the reserved tones and generating a kernel signal based on the randomly selected carrier indices; calculating a comparison reference average value of the kernel signal, comparing the calculated comparison reference average value with a prestored comparison reference average value, and preliminarily determining carrier indices of the reserved tones based on the comparison; randomly re-arranging an order of the preliminarily determined carrier indices of the reserved tones; and calculating the comparison reference average value while changing each of the re-arranged indices of the reserved tones, and finally determining carrier indices for which the calculated comparison reference average value becomes the smallest value as carrier indices of the reserved tones.

The embodiments of the present application provide an indoor positioning system, including an information source module, a gateway, a first leaky cable and a first positioning device; where the information source module is connected to a first end of the first leaky cable through a feeder; the first positioning device is arranged between the first end of the first leaky cable and the feeder, and the first positioning device is configured to transmit a positioning signal through the first leaky cable, so as to enable the terminal to perform positioning according to the positioning signal. There is no need to set up a new positioning system, thus reducing costs for network construction as well as space requirements for the network construction.

An antenna device includes antennas to receive and transmit signals; and a processor to divide radiation patterns of combinations of the antennas into a predetermined number of characteristic patterns, and to calculate similarities of the characteristic patterns and a RSSI of each of the characteristic patterns. When the antenna device is in operation, the processor reads and analyzes RSSI of the signals received by the antennas, compares the RSSI of the signals of the antennas with the RSSI of the characteristic patterns, and determines a matched characteristic pattern group according to results of comparisons and the similarities of the characteristic patterns.