TECHNICAL FIELD

Aspects disclosed herein generally relate to system, apparatus, and method for providing wireless communication. Specifically, embodiments disclosed herein also generally relate one or more mobile devices configured to determine a cyclic delay diversity time of flight (TOF) for mobile transmitters. These aspects and others will be discussed in more detail herein.

BACKGROUND

U.S. Publication No. 2017/0367065 to Seth et al. (“Seth”) discloses systems and methods for determining locations of wireless nodes in a network architecture. In one example, an asynchronous system includes a first wireless node having a wireless device with one or more processing units and RF circuitry for transmitting and receiving communications in the wireless network architecture including a first RF signal having a first packet. The system also includes a second wireless node having a wireless device with a transmitter and a receiver to enable bi-directional communications with the first wireless node in the wireless network architecture including a second RF signal with a second packet. The one or more processing units of the first wireless node are configured to execute instructions to determine a coarse time of flight estimate of the first and second packets and a fine time estimate of the time of flight using channel information of the first and second wireless nodes.

U.S. Pat. No. 6,587,811 to Schleifer et al. (“Schleifer”) discloses a circuit that generates a test signal useful in verifying the actual delay values of individual delay stages in a digital delay line. In general, the cumulative delay of the delay line defines a window in time having its zero point anchored to the beginning of the delay line. Successive delay stages correspond to successive time bins within the overall time window. The test signal shifts at a known, linear rate in time with respect to a reference signal, which is used to initiate a test cycle. The reference signal synchronizes sampling of the test signal to the beginning of the time window. Samples of the test signal are taken at sample points determined by the actual time delays in the successive delay stages. The observed distribution of test signal edges across the time window may be used to determine the actual delay intervals of the delay line.

German publication DE102017101854A1 to Gumbmann et al. (“Gumbmann”) provides a method of detecting garment reflections is described in which a pulsed radar signal is emitted which strikes an object to be examined. The pulsed radar signal comprises at least two signal pulses of different center frequency. The reflection spectrum of the pulsed radar signal is detected and evaluated. Furthermore, a device for detecting clothing reflections is described.

U.S. Publication No. 2017/0090026 to Joshi et al. (“Joshi”) discloses techniques for a motion tracing device using radio frequency signals are presented. The motion tracing device utilizes radio frequency signals, such as WiFi to identify moving objects and trace their motion. Methods and apparatus are defined that can measure multiple WiFi backscatter signals and identify the backscatter signals that correspond to moving objects. In addition, motion of a plurality of moving objects can be detected and traced for a predefined duration of time.

SUMMARY

In at least one embodiment, a system for wireless communication is provided. The system includes a first transceiver and a first mobile device. The first mobile device includes the first transceiver and is programmed to receive a first wireless signal and a second wireless signal from a first transmitter and a second transmitter, respectively, and to process the first wireless signal and the second wireless signal based on a first internal clock associated with the first mobile device. The first mobile device is further programmed to determine a time of arrival (TOA) of the first wireless signal to provide a first TOA signal and to determine the TOA of the second wireless signal to provide a second TOA signal. The first mobile device is further programmed to obtain a difference between the first TOA signal and the second TOA signal to provide a first difference TOA signal that is independent of the first internal clock.

In at least another embodiment, a method for wireless communication is provided. The method includes receiving, at a first mobile a first wireless signal and a second wireless signal from a first transmitter and a second transmitter, respectively, and processing the first wireless signal and the second wireless signal based on a first internal clock associated with the first mobile device. The method further includes determining a time of arrival (TOA) of the first wireless signal to provide a first TOA signal and determining the TOA of the second wireless signal to provide a second TOA signal. The method further includes obtaining a difference between the first TOA signal and the second TOA signal to provide a first difference TOA signal that is independent of the first internal clock.

In at least another embodiment, a computer-program product embodied in non-transitory computer readable medium that is programmed for wireless communication is provided. The computer-program product includes instructions to receive, at a first mobile a first wireless signal and a second wireless signal from a first transmitter and a second transmitter, respectively, and to process the first wireless signal and the second wireless signal based on a first internal clock associated with the first mobile device. The computer-program product includes instructions to determine a time of arrival (TOA) of the first wireless signal to provide a first TOA signal and to determine the TOA of the second wireless signal to provide a second TOA signal. The computer-program product includes instructions to obtain a difference between the first TOA signal and the second TOA signal to provide a first difference TOA signal that is independent of the first internal clock.

In at least another embodiment, a system for wireless communication is provided. The system includes a first mobile device, a second mobile device, and a server. The first mobile device is programmed to receive a first wireless signal and a second wireless signal from a first transmitter and a second transmitter, respectively and to determine a time of arrival (TOA) of the first wireless signal to provide a first TOA signal. The first mobile device is further programmed to determine the TOA of the second wireless signal to provide a second TOA signal. The second mobile device is programmed to determine a time of arrival (TOA) of the first wireless signal to provide a third TOA signal and to determine the TOA of the second wireless signal to provide a fourth TOA signal. The server is programmed to receive first information corresponding to the first TOA signal and to the second TOA signal from the first mobile device and to receive second information corresponding to the third TOA signal and to the fourth TOA signal from the second mobile device. The server is further programmed to identify a location of the first mobile device based on at least the first information and the second information, and on at least known locations of the second mobile device, the first transmitter, and the second transmitter. The server is further programmed to identify a location of the first transmitter based on at least the first information and the second information, and on at least known locations of first mobile device, the second mobile device, and the second transmitter.

