Method for modulating and demodulating data

• US 8,594,175 B2
• Filed: 10/28/2009
• Issued: 11/26/2013
• Est. Priority Date: 11/18/2008
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute, INHA Industry Partnership Institute
• Original Assignee: Electronics and Telecommunications Research Institute, INHA Industry Partnership Institute
• Inventors: Lee, Hyung Soo, Kim, Jaehwan, Kim, Jae Young, Kim, Jae Moung, Hwang, Jae Ho, Jang, Sung Jeen, Choi, Nack Hyun, Park, Jong Seok
• Primary Examiner(s): Ghulamali, Qutbuddin
• Application Number:
  US12/607,243
• Publication Number:
  US 20100124269A1
• Time in Patent Office: 1,490 Days
• Field of Search: 375/239, 375/237, 375/241, 375/242, 375/286, 375/359, 375/361, 455/23
• US Class Current: 375/239
• CPC Class Codes: H03K 7/04 Position modulation, i.e. PPM
• CPC Class Codes: H03K 9/04 of position-modulated pulses
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation

Abstract

Disclosed is a method for modulating and demodulating data. The method composes symbols by grouping a plurality of symbols for pulse position modulation to newly add symbol compositions to fixed symbols used for the pulse position modulation of the related art. Further, the method uses grouped symbols to improve data transmission rate as the average amount of information increases.

Claims

1. A method for modulating data using a pulse position modulation manner by a transmitter, comprising:

reading symbol compositions mapped to input data from a symbol mapping table that includes symbol compositions represented by a plurality of grouped symbols; and

modulating the data using the mapped symbol compositions,

wherein the symbol mapping table includes

a first symbol composition group including symbol compositions that are composed of a plurality of symbols having burst pulses positioned in all pulse periods, wherein the reading includes,

when a first bit of the input data is a first value, reading symbol compositions corresponding to the values of the remaining bits other than the first bit of the input data bits among the symbol compositions included in the first symbol composition group as the mapped symbol compositions, and wherein

the symbol mapping table further includes a second symbol composition group including the symbol compositions that are composed of a plurality of symbols having burst pulses positioned only in one pulse period for each symbol, and

the reading further includes,

when the first bit of the input data is a second value, reading symbol compositions corresponding to the values of remaining bits other than the first bit of the input data bits among the symbol compositions included in the second symbol composition group as the mapped symbol compositions.

2. The method for modulating data of claim 1, wherein

the modulating includes simultaneously modulating the plurality of symbols included in the mapped symbol compositions.

3. A method for modulating data using a pulse position modulation manner by a transmitter, comprising:

when a first bit of input data is a first value, determining pulse positions of each of a plurality of grouped symbols corresponding to each of the remaining bits other than the first bit of the input data bits;

when the first bit is a second value different from the first value, positioning burst pulses in all the pulse periods of one of a first symbol and a second symbol among the plurality of grouped symbols according to the value of the second bit of the input data; and

determining pulse positions of the remaining symbols other than the symbols having the burst pulses in all the pulse periods among the plurality of grouped symbols according to the values of the remaining bits other than the first bit and the second bit of the input data bits, wherein the determining the pulse positions of each of the plurality of grouped symbols includes positioning the burst pulses in one of the pulse periods of the corresponding symbol of the plurality of grouped symbols according to each value of the remaining bits, and wherein the determining includes, when the second bit is the first value, positioning the burst pulses in all the pulse periods of the first symbol and positioning the burst pulses in one of the plurality of pulse periods included in the remaining symbols other than the first symbol among the plurality of grouped symbols according to the values of the remaining bits other than the first bit and the second bit of the input data bits.

4. The method for modulating data of claim 3, wherein the first symbol is one of the first symbol and the final symbol of the plurality of symbols.

5. The method for modulating data of claim 3, wherein the pulse positions of the remaining symbols are determined based on 4PPM method.

6. A method for demodulating data modulated using a pulse position modulation method by a receiver, comprising:

measuring energy of a plurality of input symbols;

determining a value of a first bit according to whether the energy of a first symbol and a second symbol of the plurality of symbols is the same;

when the value of the first bit is determined to be a first value, determining the values of the remaining bits other than the first bit according to pulse positions of each of the plurality of symbols;

when the value of the first bit is determined to be a second value different from the first value, determining a value of a second bit by comparing the energy of the first symbol and the second symbol; and

when the value of the second bit is determined, determining the values of the remaining bits other than the first bit and the second bit according to the pulse positions of the remaining symbols other than the first symbol if the first symbol has a larger energy than the second symbol, or other than the second symbol if the second symbol has a larger energy than the first symbol.

7. The method for demodulating data of claim 6, wherein the determining the value of the first bit includes determining whether the energy of the first symbol and the second symbol is the same, wherein whether the energy of the first symbol and the second symbol is the same is based on whether the difference in energy between the first symbol and the second symbol Is equal to or less than a threshold value.

8. The method for demodulating data of claim 7, wherein the determining the values of the remaining bits other than the first bit includes determining the values of the corresponding bits according to a pulse period where burst pulses are positioned among pulse periods included in each of the plurality of symbols.

9. The method for demodulating data of claim 7, wherein the determining the value of the second bit includes, when the energy of the first symbol has a greater threshold value than the energy of the second symbol, determining the value of the second bit to be the first value, and when the energy of the second symbol has a greater threshold value than the energy of the first symbol, determining the value of the second bit to be the second value.

10. The method for demodulating data of claim 9, wherein the determining the values of the remaining bits other than the first bit and the second bit includes, when the energy of the first symbol has a larger threshold value than the energy of the second symbol, determining the values of the remaining bits other than the first bit and the second bit according to the pulse period where the burst pulses are positioned among the pulse periods included in the remaining symbols other than the first symbol of the plurality of symbols.