Communication system using length shift keying modulation

• US 20070121735A1
• Filed: 08/07/2006
• Published: 05/31/2007
• 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, Kim, Young-hwan, Lee, Seong-soo
• Granted Patent: US 7,933,320 B2
• Time in Patent Office: Days
• US Class Current: 375/259
• 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 combinations of data bits, and generating a communication signal including the carrier signals having the adjusted lengths.

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 8, 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.

10. The communication system as claimed in claim 9, 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.

11. The communication system as claimed in claim 10, 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.

12. The communication system as claimed in claim 9, 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.

13. The communication system as claimed in claim 9, 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.

14. 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.

15. 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.

16. 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.

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

generating carrier signals;

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

outputting a communication signal including the modulated carrier signals.

18. The method of claim 17, further comprising:

receiving the output communications signal, said receiving comprising;

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

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