Abstract: A wireless system device is a device to be mounted on a vehicle. The wireless system device includes a wireless communication unit, a condition detector, a position obtainer, and an operation controller. The wireless communication unit transmits a radio signal. The condition detector detects a first timing and a second timing. The first timing is a timing when the vehicle shifts from an operation state to a stop state. The second timing is a timing when the vehicle shifts from the stop state to the operation state for a first time after the first timing. The position obtainer obtains a first position and a second position. The first position and the second position are positions where the vehicle is at the first timing and the second timing, respectively. The operation controller controls operation of the wireless communication unit based on a distance between the first position and the second position.

Abstract: A wireless system device is a device to be mounted on a vehicle. The wireless system device includes a wireless communication unit, a condition detector, a position obtainer, and an operation controller. The wireless communication unit transmits a radio signal. The condition detector detects a first timing and a second timing. The first timing is a timing when the vehicle shifts from an operation state to a stop state. The second timing is a timing when the vehicle shifts from the stop state to the operation state for a first time after the first timing. The position obtainer obtains a first position and a second position. The first position and the second position are positions where the vehicle is at the first timing and the second timing, respectively. The operation controller controls operation of the wireless communication unit based on a distance between the first position and the second position.

Abstract: A receiver block comprises a receiver circuit, a down-converter, a mixer, a modulator circuit, a decoding circuit, a synchronization circuit, a spread code control unit, and a frequency synthesizer. No synchronization holding circuit is needed. MSFK and PSK are used as a primary modulation. Synchronization is initially acquired by repeatedly mixing a part of the frequency hopping code sequence. Synchronization is improved during a period arranged separately from data communication periods. Before data transmission, the primary modulation components are fixed and transmitted for two code periods. The time changes in phases attributed to secondary modulation components will be known. After this, the primary modulation components are found.

Abstract: Frequencies (f1 to f7) are selected in respective time slots (T1 to T7) according to digital data to be transmitted. Digital data to be transmitted is indicated by a combination of frequencies selected in the respective time slots. Since a single time slot can select a plurality of frequencies, e.g., f2, f4 and f5, the total number of frequency patterns which can be achieved is increased. Therefore, since the number of combined patterns of substantially available frequencies is also increased, the number of bits of digital data which can be transmitted in a single data cycle (a period related to T1 to T7) is increased, and a transmission efficiency is improved.

Abstract: For spread spectrum communication using a frequency hopping method, this invention is to provide a method and an apparatus for two-way simultaneous communication for transmitting/receiving with a compact circuit and without lowering a transmission rate. Data to be transmitted is encoded by an encoder circuit, and modulated by a modulator circuit according to FSK or PSK. On the other hand, a frequency synthesizer outputs a spread sequence series for frequency hopping according to a spread sequence control. The output signal from a modulator circuit is mixed by a mixer with the output signal from the frequency synthesizer. The frequency of the output signal from the mixer is shifted to a radio-frequency band by an up converter, and transmitted through a transmitting circuit. The receiver down-converts the received signal and mixes it with the output signal from the frequency synthesizer to extract significant data.

Abstract: There is show a frequency hopping communication system. When a coding circuit 1 informs a spreading code control unit 17 of an error generation, it specifies an erred carrier frequency and counts the errors for each hopping frequency. If the counted errors exceed a fixed value in a frequency, the spreading code control unit 17 changes it to another unused frequency and informs a data communication control unit 14 of changed data. The data communication control unit 14 sends the changed data to the other party apparatus as control data. The other party apparatus receives the control data and recognizes them and changes currently used hopping frequency to a corresponding new one.