Patent application number | Description | Published |
20080232431 | Electronic key system and method - An in-vehicle LF transmitter transmits a synchronization signal to an in-vehicle RF receiver and transmits LF data (response request) including a synchronization signal to a portable device. The portable device performs RF data output and DSSS process and transmits RF data (response) subjected to spread process. The in-vehicle RF receiver receives the RF data and performs despread process. Both of the spread process of the portable device and the despread process of the in-vehicle RF receiver are performed by the use of a spread code the period of which is adjusted based on the synchronization signal transmitted from the in-vehicle LF transmitter. | 09-25-2008 |
20090207892 | Receiving device for spread spectrum communication - A receiving device for spread spectrum communication includes a phase determining unit and a data demodulating unit. The receiving device receives a signal spread and modulated with first spreading code. The phase determining unit calculates a cross correlation between the received signal and a second spreading code and determines a phase P(0) of the received signal based on the cross correlation. The data demodulating unit synchronizes the phase P (0) and the first spreading code and despreads and demodulates the received signal with the first spreading code. The number of components in each of the first spreading code and the second spreading code is an integer greater than or equal to 2. | 08-20-2009 |
20090323772 | WIRELESS COMMUNICATION SYSTEM - In a wireless communication system, a portable device and an in-vehicle device wirelessly communicate with each other by a spread spectrum method. The in-vehicle device transmits a synchronization signal indicative of a reference period to the portable device. The in-vehicle device performs code acquisition for only a portion of a spread wireless signal received from the portable device. The portion has a starting point in a search period from a search start point to a search end point. The search start point is identified based on the reference period and a predetermined first correction time. The search end point is identified based on the reference period and a predetermined second correction time. | 12-31-2009 |
20100003940 | RADIO SIGNAL RECEIVER DEVICE - A radio signal detector includes first and second detector circuits. The first detector circuit has a higher detection sensitivity to detect a radio signal earlier than the second detector circuit. The second detector circuit has a lower detection sensitivity to detect the radio signal accurately. When the second detector circuit detects the radio signal, it starts up a microcomputer. When the first detector circuit detects the radio signal, a time counter starts to count time. After being started up, the microcomputer acquires a time difference between the radio signal detection by the first detector circuit and the start-up. The microcomputer determines time of radio signal transmission by a radio signal transmitter device based on the determined time difference, and outputs control information after an elapse of a predetermined time. | 01-07-2010 |
20100232478 | Receiver for spread spectrum communication - A receiver for spread spectrum communication includes a receiver for receiving a wireless signal, a demodulator for demodulating the wireless signal into a spread spectrum signal, a correlation value calculator for calculating a correlation value between the spread spectrum signal and a spreading code having a predetermined number of chips, a synchronization detector for detecting a synchronization point between the spread spectrum signal and the spread signal based on the correlation value, a despreading device for despreading the spread spectrum signal based on the synchronization point, a noise level detector for detecting a noise level of the wireless signal, and a code number setting device for determining the number of chips of the spreading code in such a manner that there is a positive correlation between the noise level and the number of code portions. | 09-16-2010 |
20110128995 | Wireless communication system - In a wireless communication system, a portable device transmits a first signal spread based on a reference period indicated by a synchronization signal transmitted from an in-vehicle device and transmits a second signal spread based on an operation by a user. The in-vehicle device sets a search period based on a variation range in a delay time from when the synchronization signal is transmitted to when the spread first signal is transmitted and sets a residual period that starts at an ending point of the search period and ends at an ending point of the reference period when a starting point of the reference period is set at a starting point of the search period. When the in-vehicle device fails in a synchronous acquisition for the search period, the in-vehicle device performs a synchronous acquisition process for the residual period. | 06-02-2011 |
20130196610 | WIRELESS COMMUNICATION SYSTEM - A first communication apparatus and a second communication apparatus are capable of wireless communication with each other. The first communication apparatus has a normal operation mode and a tuning mode that differs from the normal operation mode and allows a variable matching portion to adjust a matching state. When the tuning mode is selected, the first transmission portion transmits an operation mode transition request signal to the second communication apparatus. A first reception portion receives a tuning reference signal transmitted from the second communication apparatus in response to the operation mode transition request signal. A reception signal intensity measurement portion measures a reception signal intensity of the received tuning reference signal. The variable matching portion adjusts a matching state based on the measured reception signal intensity of the tuning reference signal. | 08-01-2013 |
20150243156 | VEHICLE COMMUNICATION DEVICE - A vehicle communication device includes: a communication line establishment device that establishes a communication line with a mobile communication terminal; a manipulation state information transmission device that transmits manipulation state information indicating a manipulation state of a vehicular accessory to the mobile communication terminal; an output timing specifying information generation device that generates output timing specifying information for specifying separation of the mobile communication terminal from the vehicle as an output timing for the mobile communication terminal to output the manipulation state information; and an output timing specifying information transmission device that transmits the output timing specifying information to the mobile communication terminal. | 08-27-2015 |