Communication system using length shift keying modulation method

• US 7,933,320 B2
• Filed: 08/07/2006
• Issued: 04/26/2011
• Est. Priority Date: 11/29/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Jae-hyon, Lee, Seong-soo, Kim, Young-hwan
• Primary Examiner(s): Odom; Curtis B
• Application Number:
  US11/499,700
• Publication Number:
  US 20070121735A1
• Time in Patent Office: 1,723 Days
• Field of Search: 375/223, 375/271, 32155-158
• US Class Current: 375/223
• CPC Class Codes: H04L 27/00 Modulated-carrier systems

Abstract

A communication system using a length shift keying (LSK) modulation method provides a transmitter having a carrier signal generator for generating carrier signals, and a modulator for modulating lengths of the carrier signals from the carrier signal generator according to combinations of data bits, and a receiver having an integrator for calculating an energy value by integrating the carrier signal that corresponds to a data bit combination, and a data judgment unit for judging the data bit combination by comparing the energy value with a predetermined threshold value. Power is maintained without changing the bandwidth of a communication signal when the communication signal is modulated.

Claims

1. A communication system using a length shift keying (LSK) modulation method, the communication system comprising a transmitter that adjusts lengths of carrier signals for transmitting data in a time domain according to predetermined combinations of data bits, and generating a communication signal including the carrier signals having the adjusted lengths,

wherein the carrier signal is adjusted to a different lengths according to each predetermined combination of data bits.

2. The communication system as claimed in claim 1, wherein the transmitter comprises:

a carrier signal generator that generates the carrier signals; and

a modulator that modulates the lengths of the carrier signals generated by the carrier signal generator according to the combinations of the data bits, and outputs the communication signal including the modulated carrier signals.

3. The communication system as claimed in claim 2, wherein the modulator has information on the combinations of the data bits and the lengths of the carrier signals set to correspond to the combinations of the data bits.

4. The communication system as claimed in claim 2, wherein the number of combinations of the data bits stored in the modulator and the number of kinds of carrier signals are a square multiple of 4.

5. The communication system as claimed in claim 2, wherein the carrier signals have different lengths at integer times according to the data bits.

6. The communication system as claimed in claim 2, wherein the modulator generates an interval in which no carrier signal exists between neighboring carrier signals by stopping the output of the carrier signal.

7. The communication system as claimed in claim 6, wherein the interval is longer than or equal to a length of a longest carrier signal among the carrier signals.

8. The communication system as claimed in claim 2, further comprising a receiver which receives the communication signal generated by the modulator, and judges the data bits according to the lengths of the carrier signals included in a specified section of the communication signal.

9. The communication system as claimed in claim 1, wherein a number of the predetermined combinations of data bits is represented by at least two sequence of numbers using ‘

0’

or ‘

1’

.

15. The communication system as claimed in claim 1, wherein the carrier signal generator generates at least one of a chaotic signal, an impulse signal, and a spreading sequence signal.

10. A communication system using a length shift keying (LSK) modulation method, the communication system comprising:

a transmitter that adjusts lengths of carrier signals for transmitting data in a time domain according to combinations of data bits, and generates a communication signal including the carrier signals having the adjusted lengths,

wherein the transmitter comprises;

a carrier signal generator that generates the carrier signals; and

a modulator that modulates the lengths of the carrier signals generated by the carrier signal generator according to the combinations of the data bits, and outputs the communication signal including the modulated carrier signals; and

a receiver which receives the communication signal generated by the modulator, and judges the data bits according to the lengths of the carrier signals included in a specified section of the communication signal,

wherein the receiver comprises;

an integrator that calculates an energy value by integrating the carrier signal that corresponds to a data bit combination; and

a data judgment unit that judges the data bit combination by comparing the energy value with a threshold value.

11. The communication system as claimed in claim 10, wherein the data judgment unit has a number of threshold values which is equal to a number of the combinations of the data bits stored in the modulator.

12. The communication system as claimed in claim 11, wherein the respective threshold values are set to have successive values at a predetermined interval between neighboring threshold values, according to the corresponding combinations of the data bits.

13. The communication system as claimed in claim 10, wherein the integrator sets a range of the lengths of the carrier signal that corresponds to a data bit combination using a window having a same length as that of a shortest carrier signal among the carrier signals.

14. The communication system as claimed in claim 10, wherein the integrator sets a range of the lengths of the carrier signal that corresponds to a data bit combination using a window having a same length as that of a longest carrier signal among the carrier signals.

16. The communication system as claimed in claim 10, wherein a number of the predetermined combinations of data bits is represented by a sequence of at least two numbers using ‘

0’

or ‘

1’

.

17. A communication system using a length shift keying (LSK) modulation method, the communication system comprising:

a transmitter that includes a carrier signal generator that generates carrier signals, and a modulator that modulates lengths of the carrier signals generated by the carrier signal generator according to combinations of data bits and outputs the modulated carrier signals; and

a receiver that includes an integrator that calculates an energy value by integrating a carrier signal that corresponds to a data bit combination, and a data judgment unit that judges the data bit combination by comparing the energy value with a predetermined threshold value.

18. The communication system as claimed in claim 17, wherein a number of predetermined combinations of data bits is represented by a sequence of at least two numbers using ‘

0’

or ‘

1’

.

19. A communication system using a length shift keying (LSK) modulation method, the communication system comprising:

means for generating carrier signals;

means for modulating lengths of the carrier signals according to combinations of data bits;

means for outputting a communication signal including the modulated carrier signals; and

means for receiving the output communications signal, the means for receiving comprising;

means for calculating an energy value by integrating the carrier signal corresponding to a data bit combination; and

means for judging the data bit combination by comparing the energy value with a predetermined threshold value.

20. The communication system as claimed in claim 19, wherein a number of the predetermined combinations of data bits is represented by a sequence of at least two numbers using ‘

0’

or ‘

1’

.

21. A length shift keying (LSK) modulation method comprising:

generating carrier signals by a carrier signal generator;

modulating, by a modulator, lengths of the carrier signals according to predetermined combinations of data bits; and

outputting a communication signal including the modulated carrier signals,

wherein in the modulating, the lengths of the carrier signals are modulated two different lengths according to each predetermined combination of data bits.

22. The method of claim 21, further comprising:

receiving the output communications signal, said receiving comprising;

integrating, by an integrator, the carrier signal corresponding to a data bit combination to calculate an energy value; and

judging, by a data judgment unit, the data bit combination by comparing the energy value with a predetermined threshold value.

23. The method of claim 21, wherein a number of the predetermined combinations of data bits is represented by a sequence of at least two numbers using ‘

0’

or ‘

1’

.