Abstract: Methods and systems for estimating range between a first device and a second device using at least one wireless communication channel defined between the first and second devices are disclosed. The method comprises: obtaining a set of range measurements, wherein the range measurements include measurements associated with multiple paths taken by signals between the first and second devices; discarding over-ranges caused by multiple signal paths using a variable threshold; and processing the remaining range measurements to obtain an estimated range.

Abstract: Disclosed herein is a method and system for determining plausibility of intelligent transport system (ITS) messages via a wireless communications channel at one or more message receivers. The method includes receiving a first ITS message having a first characteristic and receiving a second associated ITS message having a second characteristic. The method uses the first characteristic and the second characteristic to satisfy at least one predetermined criterion and determines plausibility of at least one of the first ITS message, the second ITS message and a third ITS message. The characteristic includes a PHY-layer or MAC-layer characteristic. The method is used to distinguish between genuine and spoofed messages to reduce the possibility of an attack.

Abstract: Methods and systems for estimating the position of an object such (as a vehicle) are disclosed. The method comprises transmitting a first V2X message from the object to a plurality of spaced apart units; and receiving a set of V2X response messages from at least two units in response to the first V2X message. Each response message comprises an identifier of the object, an identifier of the unit from which the response message was sent, and temporal information associated with the times of receiving a previous V2X message at the unit and transmitting a previous V2X response message from the unit. The position of the object is estimated based on the information contained in the set of V2X response messages and the times of transmitting the previous V2X message from the object and receiving the previous set of V2X response messages at the object.

Abstract: Methods and systems for estimating the position of an object such (as a vehicle) are disclosed. The method comprises transmitting a first V2X message from the object to a plurality of spaced apart units; and receiving a set of V2X response messages from at least two units in response to the first V2X message. Each response message comprises an identifier of the object, an identifier of the unit from which the response message was sent, and temporal information associated with the times of receiving a previous V2X message at the unit and transmitting a previous V2X response message from the unit. The position of the object is estimated based on the information contained in the set of V2X response messages and the times of transmitting the previous V2X message from the object and receiving the previous set of V2X response messages at the object.

Abstract: Methods and systems for estimating range between a first device and a second device using at least one wireless communication channel defined between the first and second devices are disclosed. The method comprises: obtaining a set of range measurements, wherein the range measurements include measurements associated with multiple paths taken by signals between the first and second devices; discarding over-ranges caused by multiple signal paths using a variable threshold; and processing the remaining range measurements to obtain an estimated range.

Abstract: Disclosed herein is a method and system for determining plausibility of intelligent transport system (ITS) messages via a wireless communications channel at one or more message receivers. The method includes receiving a first ITS message having a first characteristic and receiving a second associated ITS message having a second characteristic. The method uses the first characteristic and the second characteristic to satisfy at least one predetermined criterion and determines plausibility of at least one of the first ITS message, the second ITS message and a third ITS message. The characteristic includes a PHY-layer or MAC-layer characteristic. The method is used to distinguish between genuine and spoofed messages to reduce the possibility of an attack.

Abstract: The present invention relates to a method and apparatus for channel estimation between a transmitter and a receiver in a wireless communications system.

Abstract: The present invention relates to a method and apparatus for adaptive channel estimation for signal-amplitude-based communications systems. In one arrangement, the method comprises: receiving an observation (r) of a transmitted coded symbol (d); generating, with a weight generator, a first coefficient (v) for weighting the received observation based on an estimate of the transmitted coded symbol (d_est), the first coefficient having a magnitude that is invariable with the amplitude of the transmitted coded symbol; and forming a new channel estimate (h_est) based on a weighted observation using the first coefficient (v).

Abstract: The present invention relates to a method and apparatus for demodulation in a wireless communications system transmitted across a wireless communications channel. The described wireless receiver includes a first antenna for receiving a wireless signal including a symbol transmitted across a wireless communications channel perceived by the first antenna, an observation modifier for generating a modified observation (y) of the symbol based on a product of the received observation (r) and the complex conjugate of a channel estimate (h*), a log-likelihood ratio (LLR) module generating log-likelihood ratios (LLRs) based on the modified observation and the channel estimate, and a maximum-likelihood-based decoder for decoding the symbol based on the LLRs.

Abstract: Described herein is a wireless receiver configured to receive wireless signals containing data packets transmitted according to an undetermined communications protocol selected from at least a first communications protocol and a second communications protocol. Without necessarily decoding the data packets, for example according to either the first or the second communication protocol, the described wireless receiver is able to concurrently detect presence of signal transmission in the first communications protocol or the second communications protocol. In some arrangements, the described wireless receiver may be configured to differentiate between the first communications protocol and the second communications protocol. The ability of the wireless receiver to detect presence of signal transmission by other wireless devices may provide intelligence to an associated wireless transmitter of any concurrent signal transmission so as to minimize interference.

Abstract: A method for extracting a parameter of a communication channel from a channel estimate that characterizes the communication channel in terms of a frequency response over time. The method includes generating a set of feature identifiers that characterize features of the channel, for example energy peaks or troughs and determining the parameter, for example time delay of a multipath signal or frequency offset of a multipath signal, dependent on the feature identifiers. Methods using the parameter are also described including methods to estimate the environment.

Abstract: The present invention relates to a method and apparatus for demodulation in a wireless communications system transmitted across a wireless communications channel. The described wireless receiver includes a first antenna for receiving a wireless signal including a symbol transmitted across a wireless communications channel perceived by the first antenna, an observation modifier for generating a modified observation (y) of the symbol based on a product of the received observation (r) and the complex conjugate of a channel estimate (h*), a log-likelihood ratio (LLR) module generating log-likelihood ratios (LLRs) based on the modified observation and the channel estimate, and a maximum-likelihood-based decoder for decoding the symbol based on the LLRs.

Abstract: The present invention relates to a method and apparatus for channel estimation between a transmitter and a receiver in a wireless communications system.

Abstract: The present invention relates to a method and apparatus for adaptive channel estimation for signal-amplitude-based communications systems. In one arrangement, the method comprises: receiving an observation (r) of a transmitted coded symbol (d); generating, with a weight generator, a first coefficient (v) for weighting the received observation based on an estimate of the transmitted coded symbol (d_est), the first coefficient having a magnitude that is invariable with the amplitude of the transmitted coded symbol; and forming a new channel estimate (h_est) based on a weighted observation using the first coefficient (v).

Abstract: Described herein is a wireless receiver configured to receive wireless signals containing data packets transmitted according to an undetermined communications protocol selected from at least a first communications protocol and a second communications protocol. Without necessarily decoding the data packets, for example according to either the first or the second communication protocol, the described wireless receiver is able to concurrently detect presence of signal transmission in the first communications protocol or the second communications protocol. In some arrangements, the described wireless receiver may be configured to differentiate between the first communications protocol and the second communications protocol. The ability of the wireless receiver to detect presence of signal transmission by other wireless devices may provide intelligence to an associated wireless transmitter of any concurrent signal transmission so as to minimise interference.

Abstract: The present invention relates to a split signal processing system comprising: multiple antennas for receiving transmitted signals carrying an information-bearing symbol; multiple signal processing modules associated with the respective antennas and being configured to generate respective bit log-likelihood ratio (LLR) sequences, each corresponding to the information-bearing symbol; and a LLR combiner for combining the bit LLR sequences received from the multiple signal processing modules.

Abstract: An Intelligent Transportation Systems (ITS) device is described. The ITS device (400) includes: radio resources including a receiver (402) adapted to receive a radio signal in at least two frequency bands; a channel detector (410) arranged to analyse a signal received in a first frequency band to determine the presence of a transmission in that frequency band; a controller (402) configured to control assignment of radio resources, and in the event that the channel detector detects a signal in the first frequency band, to prevent transmission of a potentially interfering radio signal. The first frequency channel can be part of another radio communications system, such as a RTTT1 SSRC radio system.

Abstract: A system and method are described for characterizing a wireless communications link as line-of-sight (LOS) or non line-of-sight (NLOS). The method comprises receiving data (T) representing a position of a transmitter, receiving data (R) representing a position of a receiver, receiving a measure of transmitted power at an output of the transmitter (PT) and receiving a measure of received power at an input to the receiver (PR). An NLOS detector (400) generates at least one non line-of-sight metric to characterize the wireless link between the transmitter and the receiver based on the position of the receiver, the position of the transmitter, the transmitted power and the received power.

Abstract: Methods and apparatus are described for improving receiver performance in a multicarrier communication network in which an encoded symbol is transmitted over a transmission channel in the communications system. A model of the transmission channel is estimated, said model characterising an effect of intercarrier interference on at least one carrier in the multicarrier system. The received symbol is decoded using the estimated model to remove a predicted effect of intercarrier interference. A pre-processor is also described for operation in conjunction with a communications receiver in the network. The pre-processor includes a channel estimator operable to estimate at least one feature of the communication channel based on a received signal. The pre-processor modifies the received signal dependent on the at least one estimated feature and provides the modified signal to the communications receiver.

Abstract: A method is for communicating by tracking time varying channels in a multiple access packet based communication network. Each packet includes a preamble portion including a data symbol, and a data portion including data symbols. The method may include initializing a channel estimate reference from an initial channel estimate based upon the data symbol in a preamble portion of a received packet, and updating the channel estimate reference based upon a channel estimate of a current data symbol and a previously received data symbol from the data symbols in a data portion of the received packet. The method may also include repeating the updating upon receipt of a subsequent data symbol from the data symbols in the data portion of the received packet.