Transmitting/receiving device and communication system using the same

1. A transmitting/receiving device with a transmitting/receiving function performing bidirectional communication with a host, the device comprising:

a synchronization control unit;

a frequency generator generating a transmitting signal; and

a reference signal generation source generating a reference signal,

wherein the reference signal generation source is formed independently of the host,

wherein the synchronization control unit detects a frequency difference of the transmitting signal with respect to a received signal from the host, outputs a frequency coordination signal reducing the difference with respect to the received signal and outputs a spread spectrum selection signal,

wherein the frequency generator determines frequency of the transmitting signal based on the reference signal, controls spread mode of the transmitting signal outputted by the spread spectrum selection signal, and coordinates the frequency of the transmitting signal by the frequency coordination signal,

wherein the synchronization control unit comprises a synchronization establishment unit, a frequency difference detector, and a frequency generator,

wherein the synchronization establishment unit converts a signal transmitted from the host to the transmitting/receiving device into data and a clock, and outputs a synchronization establishment signal, the received signal and a reception data,

wherein the frequency difference detector receives the reference signal, the synchronization establishment signal, the received signal, and a transmitting signal outputted from the frequency generator and is controlled by the synchronization establishment signal,

wherein the frequency difference detector detects the frequency difference between the received signal and the transmitting signal, and outputs the frequency coordination signal and spread spectrum selection signal,

wherein the frequency generator receives the reference signal, the frequency coordination signal and the spread spectrum selection signal and controls spread mode and frequency of a transmitting signal outputted based on the frequency coordination signal and the spread spectrum selection signal,

wherein the frequency difference detector comprises a signal detector, a sequencer, and a frequency difference detection coordinator,

wherein the signal detector to which the synchronization establishment signal is inputted judges whether synchronization is established and outputs a judgment result to the sequencer,

wherein the sequencer recognizes a sequence based on the judgment result and outputs a sequence signal to the frequency difference detection coordinator,

wherein the frequency difference detection coordinator to which the received signal, the transmitting signal, the reference signal and the sequence signal are inputted is controlled of its operation by the sequence signal, detects the frequency difference between the received signal and the transmitting signal at a detection time generated by the reference signal, and outputs the frequency coordination signal and the spread spectrum selection signal,

wherein the frequency difference detection coordinator comprises a transmitting frequency detector, a received frequency detector, and a difference detection circuit,

wherein the transmitting frequency detector to which the reference signal, the sequence signal and the transmitting signal are inputted is operated under control of the sequence signal, extracts an upper limit frequency, average frequency and lower limit frequency of the transmitting signal by counting a clock of the transmitting signal at a designated time by the reference signal, and outputs the upper limit frequency, the average frequency and the lower limit frequency to the difference detection circuit,

wherein the received frequency detector to which the reference signal, the sequence signal and the received signal are inputted is operated under control of the sequence signal, extracts an upper limit frequency, average frequency, lower limit frequency of the transmitting signal and a spread spectrum mode decision signal by counting a clock of the transmitting signal at a designated time by the reference signal, and outputs the upper limit frequency, the average frequency, the lower limit frequency and the spread spectrum mode decision signal to the difference detection circuit, and

wherein the difference detection circuit to which the upper limit frequency, average frequency and lower limit frequency of the transmitting signal and the upper limit frequency, average frequency, lower limit frequency, and spread spectrum mode decision signal of the received signal are inputted outputs the frequency coordination signal and the spread spectrum selection signal based on those inputted signals.

2. The transmitting/receiving device according to claim 1 , wherein the transmitting frequency detector comprises a counting time generator and a spread spectrum mode detector,

wherein the counting time generator to which the reference signal is inputted generates a counting time of the spread spectrum mode detector and outputs the time to the spread spectrum mode detector, and

wherein the spread spectrum mode detector to which the transmitting signal, the counting time and the sequence signal are inputted is operated under control of the sequence signal, and generates and extracts the upper limit frequency, the average frequency and the lower limit frequency by counting a clock of the transmitting signal during an interval specified by the counting time.

3. The transmitting/receiving device according to claim 1 , wherein the received frequency detector comprises a counting time generator and a spread spectrum mode detector,

wherein the counting time generator to which the reference signal is inputted generates a counting time of the spread spectrum mode detector and outputs the time to the spread spectrum mode detector, and

wherein the spread spectrum mode detector to which the received signal, the counting time and the sequence signal are inputted is operated under control of the sequence signal, and generates and extracts the upper limit frequency, the average frequency and the lower limit frequency by counting a clock of the received signal during an interval specified by the counting time.

4. A transmitting/receiving device with a transmitting/receiving function performing bidirectional communication with a host, the device comprising:

a synchronization control unit;

a frequency generator generating a transmitting signal; and

a reference signal generation source generating a reference signal,

wherein the synchronization control unit detects a frequency difference of the transmitting signal with respect to a received signal from the host and outputs a frequency coordination signal reducing the difference with respect to the received signal;

wherein the frequency generator determines the frequency of the transmitting signal based on the reference signal and coordinates the frequency of the transmitting signal by the frequency coordination signal,

wherein the reference signal generation source is formed independently of the host,

wherein the synchronization control unit detects the frequency difference of the transmitting signal with respect to a received signal from the host, outputs a frequency coordination signal reducing the difference with respect to the received signal, and outputs a spread spectrum selection signal, and detects a frequency modulation factor of the transmitting signal with respect to the received signal and outputs the frequency modulation factor coordination signal reducing the difference with respect to the received signal,

wherein the frequency generator determines frequency of the transmitting signal based on the reference controls spread mode of the transmitting signal outputted by the spread spectrum selection signal, coordinates the frequency of the transmitting signal by the frequency coordination signal, and coordinates the frequency modulation factor of the transmitting signal by the frequency modulation factor coordination signal,

wherein a synchronization establishment unit of the synchronization control unit converts a signal transmitted from the host to the transmitting/receiving device into data and a clock, and outputs them as a synchronization establishment signal, the received signal and a reception data,

wherein a frequency difference detector of the synchronization control unit, to which the reference signal, the synchronization establishment signal, the received signal, and a transmitting signal outputted from the frequency generator are inputted, is controlled by the synchronization establishment signal, detects the frequency difference and a frequency modulation factor difference between the received signal and the transmitting signal, and outputs a frequency coordination signal, a spread spectrum selection signal, and a frequency modulation factor coordination signal, and

wherein a frequency generator of the synchronization control unit, to which the reference signal, the frequency coordination signal, the spread spectrum selection signal, and the frequency modulation factor coordination signal are inputted, controls spread mode and frequency of a transmitting signal outputted by the frequency coordination signal, the spread spectrum selection signal and the frequency modulation factor coordination signal.

5. The transmitting/receiving device according to claim 4 , wherein the frequency difference detector comprises a signal detector, a sequencer, and a frequency difference detection coordinator,

wherein the signal detector to which the synchronization establishment signal is inputted judges whether synchronization is established and outputs a judgment result to the sequencer,

wherein the sequencer recognizes a sequence based on the judgment result and outputs a sequence signal to the frequency difference detection coordinator,

wherein the frequency difference detection coordinator to which the received signal, the transmitting signal, the reference signal and the sequence signal are inputted is controlled of its operation by the sequence signal, detects the frequency difference between the received signal and the transmitting signal at a detection time generated by the reference signal, and outputs the frequency coordination signal, the spread spectrum selection signal, and the frequency modulation factor coordination signal.

6. The transmitting/receiving device according to claim 5 , wherein the frequency difference detection coordinator comprises a transmitting frequency detector, a received frequency detector, and a difference detection circuit,

wherein the transmitting frequency detector to which the reference signal, the sequence signal and the transmitting signal are inputted is operated under control of the sequence signal, extracts an upper limit frequency and lower limit frequency of the transmitting signal by counting a clock of the transmitting signal at a designated time by the reference signal, and outputs the upper limit frequency and the lower limit frequency to the difference detection circuit, and

wherein the received frequency detector to which the reference signal, the sequence signal, and the received signal are inputted is operated under control of the sequence signal, extracts an upper limit frequency, lower limit frequency of the transmitting signal and a spread spectrum mode decision signal by counting a clock of the transmitting signal at a designated time by the reference signal, and outputs the upper limit frequency, the lower limit frequency and the spread spectrum mode decision signal to the difference detection circuit, and

wherein the difference detection circuit to which the upper limit frequency and lower limit frequency of the transmitting signal and the upper limit frequency and lower limit frequency of the received signal and spread spectrum mode decision signal are inputted outputs the frequency coordination signal, the spread spectrum selection signal, and the frequency modulation factor coordination signal based on those inputted signals.

7. The of the received signal according to claim 6 , wherein the transmitting frequency detector comprises a counting time generator and a spread spectrum mode detector,

wherein the counting time generator to which the reference signal is inputted generates a counting time of the spread spectrum mode detector and outputs the time to the spread spectrum mode detector, and

wherein the spread spectrum mode detector to which the transmitting signal, the counting time and the sequence signal are inputted is operated under control of the sequence signal, and generates and extracts the upper limit frequency, the average frequency and the lower limit frequency by counting a clock of the transmitting signal during an interval specified by the counting time.

8. The of the received signal according to claim 6 , wherein the received frequency detector comprises a counting time generator and a spread spectrum mode detector,

wherein the counting time generator to which the reference signal is inputted generates a counting time of the spread spectrum mode detector and outputs the time to the spread spectrum mode detector, and

wherein the spread spectrum mode detector to which the received signal, the counting time and the sequence signal are inputted is operated under control of the sequence signal, and generates and extracts the upper limit frequency, the average frequency and the lower limit frequency by counting a clock of the received signal during an interval specified by the counting time.