TRANSMITTING APPARATUS, RECEIVING APPARATUS AND COMMUNICATION SYSTEM

• US 20100040168A1
• Filed: 03/09/2006
• Published: 02/18/2010
• Est. Priority Date: 03/29/2005
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kunieda, Yoshinori, Ueki, Noriyuki, Mimura, Masahiro, Fujita, Suguru, Takahashi, Kazuaki
• Granted Patent: US 8,254,437 B2
• Time in Patent Office: Days
• US Class Current: 375/295
• CPC Class Codes: H04B 1/7174 Pulse generation in general H04L25/03834
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence

Abstract

A transmitting apparatus, receiving apparatus and communication system are disclosed, and great improvement in an S/N ratio, preventing an actual throughput from decreasing, and preventing the number of circuits for synchronizing spread spectrum signals from increasing can be expected at the receiving apparatus side. The transmitting apparatus includes a pulse generating circuit, pulse repetition cycle determining circuit, peak power determining circuit, and modulator. The pulse generating circuit generates pulse strings, pulse repetition cycle determining circuit determines, based on a clock signal, a pulse repetition cycle of the pulse string generated by the pulse generating circuit. The peak power determining circuit determines a pulse peak power of the pulse string. The modulator modulates the pulse string with transmission data, and then generates a transmission signal.

Claims

1. A transmitting apparatus comprising:

a pulse generating circuit for generating a pulse string;

a pulse repetition cycle determining circuit for determining a pulse repetition cycle of the pulse string based on a clock signal;

a peak power determining circuit for determining a pulse peak power of the pulse string; and

a modulator for modulating the pulse string with transmission data for generating a transmission signal,

wherein cooperation of the pulse repetition cycle determining circuit with the peak power determining circuit determines the pulse repetition cycle and the pulse peak power so that an average power of the transmission signal can be constant.

3. The transmitting apparatus of claim 1, wherein the transmission signal is formed of at least two kinds of pulses having different peak values from each other.

4. The transmitting apparatus of claim 1, wherein the modulator allots at least a part of sync information to a pulse having a great pulse peak power.

5. The transmitting apparatus of claim 1, wherein the modulator allots a signal to be used for measuring a distance to a pulse having a great pulse peak power.

6. The transmitting apparatus of claim 1, wherein the modulator employs one of pulse position modulation, pulse phase modulation, and pulse amplitude modulation as a modulating method.

7. The transmitting apparatus of claim 1 further comprises a random number generating circuit for generating a random number, wherein the peak power determining circuit determines, based on the random number, a pulse peak power of a pulse having a great peak power.

8. The transmitting apparatus of claim 1 further comprises a timer circuit for designating a time interval, wherein the peak power determining circuit determines the pulse peak power based on the designated time interval.

9. The transmitting apparatus of claim 1, wherein the transmitting apparatus changes, based on information received by a receiving apparatus, at least one of a pulse repetition cycle determined by the pulse repetition cycle determining circuit and a pulse peak power determined by the peak power determining circuit.

10. The transmitting apparatus of claim 9, wherein information received by the receiving apparatus indicates a reception status of a communication counterpart device to which the transmission signal is sent.

11. The transmitting apparatus of claim 9, wherein information received by the receiving apparatus is sent from a device other than the communication counterpart device to which the transmission signal is sent.

2. (canceled)

12. A receiving apparatus comprising:

a reception pulse signal generating circuit for reproducing a short pulse based on a reception signal, and generating a reception pulse signal;

a selecting circuit for selecting a pulse based on an amount of a pulse peak power of the reception pulse signal;

a synchronizing circuit for synchronizing a clock signal with a reception pulse signal selected by the selecting circuit, and then generating a sync output signal; and

a demodulating circuit for generating a demodulated signal by using a sync output signal supplied from the synchronizing circuit and a reception pulse signal supplied from the selecting circuit.

13. The receiving apparatus of claim 12, wherein the selecting circuit selects a pulse having a great pulse peak power, and the synchronizing circuit synchronizes the clock signal with the pulse selected by the selecting circuit and having a great pulse peak power, and the demodulating circuit receives and demodulates a pulse having a small pulse peak power.

14. The receiving apparatus of claim 12, wherein the selecting circuit selects a pulse having a great pulse peak power, and the synchronizing circuit synchronizes a spread signal with the pulse selected by the selecting circuit and having a great pulse peak power.

15. The receiving apparatus of claim 12 further comprising:

a time difference signal generating circuit for generating a time difference signal based on a time difference between the clock signal and the reception pulse signal; and

a signal flight distance estimating circuit for estimating a flight distance of a signal by using the time difference signal.

16. The receiving apparatus of claim 12, wherein the demodulating circuit obtains reception information about another device, and outputs the information to a transmitting apparatus.

17. The receiving apparatus of claim 16, wherein the another device is a communication counterpart device of the transmitting apparatus.

18. The receiving apparatus of claim 16, wherein the another device is a device other than a communication counterpart device of the transmitting apparatus.

20. The receiving apparatus of claim 12, wherein the receiving apparatus includes a reception status estimating circuit for estimating a communication status based on a change in phases of a sync output signal generated by the synchronizing circuit, and the reception status estimating circuit determines at least one of a peak power of a pulse sent by the transmitting apparatus and having a great peak power, and the pulse repetition cycle based on the change in phases.

21. The receiving apparatus of claim 20, wherein the synchronizing circuit determines, based on an average value of phase changes of a sync output signal generated by the synchronizing circuit, at least one of the peak power of the pulse and the pulse repetition cycle.

19. (canceled)