SIGNAL TRANSMISSION DEVICE ADJUSTING ELECTRICAL CHARACTERISTIC VALUE CORRESPONDING TO LOGIC LEVEL AND SIGNAL TRANSMITTING METHOD THEREOF

• US 20150215147A1
• Filed: 01/13/2015
• Published: 07/30/2015
• Est. Priority Date: 01/27/2014
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: JANG, Seunghyun, CHO, Young Kyun, LEE, Sung Jun, PARK, Bong Hyuk, JUNG, JAE HO, LEE, Kwangchun
• Granted Patent: US 9,300,513 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 25/4923 using ternary codes H04L25/4927 takes precedence
• CPC Class Codes: H04L 27/20 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/2627 Modulators
• CPC Class Codes: H04L 27/368 adaptive predistortion

Abstract

Provided is a signal transmission device including a first modulation unit generating a first modulated signal having at least three logic levels by modulating an input signal; a characteristic adjustment unit generating an adjusted first modulated signal by adjusting the at least one of electrical characteristic values based on an adjustment signal; a second modulation unit generating a second modulated signal by modulating the adjusted first modulated signal; and an adjustment operation unit generating the adjustment signal based on electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal and corresponding to at least three logic levels of the second modulated signal. Linearity of the modulated signal generated by the provided signal transmission device is enhanced.

Claims

1. A signal transmission device comprising:

a first modulation unit configured to generate a first modulated signal having at least three logic levels by modulating an input signal;

a characteristic adjustment unit configured to generate an adjusted first modulated signal by adjusting at least one of electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal, based on an adjustment signal;

a second modulation unit configured to generate a second modulated signal by modulating the adjusted first modulated signal based on a carrier signal;

a power amplification unit configured to amplify power of the second modulated signal to output an amplified second modulated signal; and

an adjustment operation unit configured to generate the adjustment signal based on the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal and electrical characteristic values respectively corresponding to at least three logic levels of the amplified second modulated signal.

2. The signal transmission device of claim 1, wherein the first modulation unit is configured to generate the first modulated signal by using at least one of delta-sigma modulation and pulse width modulation.

3. The signal transmission device of claim 1, wherein the characteristic adjustment unit is configured to adjust the at least one of the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal such that a ratio of differences between each of the electrical characteristic values respectively corresponding to the at least three logic levels of the amplified second modulated signal is being same as a ratio of differences between each of the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal, based on the adjustment signal.

4. The signal transmission device of claim 1, wherein the first modulation unit is further configured to receive a signal corresponding to amplitude information of the input signal, and

wherein the second modulation unit is further configured to receive a signal corresponding to phase information of the input signal.

5. The signal transmission device of claim 1, further comprising an initial-characteristic-providing unit configured to provide the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal to the adjustment operation unit.

6. The signal transmission device of claim 5, wherein the initial-characteristic-providing unit comprises an initial characteristic detector configured to detect the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal.

7. The signal transmission device of claim 5, wherein the initial-characteristic-providing unit comprises a look-up table configured to store the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal.

8. The signal transmission device of claim 7, wherein at least one of the electrical characteristic values stored in the look-up table is updated based on at least one of the adjustment signal and the adjusted first modulated signal.

9. The signal transmission device of claim 1, further comprising an output characteristic detection unit configured to detect the electrical characteristic values respectively corresponding to the at least three logic levels of the amplified second modulated signal.

10. A signal transmitting method comprising:

generating a first modulated signal having at least three logic levels by modulating an input signal;

amplifying power of the first modulated signal to generate an amplified first modulated signal;

generating an adjustment signal based on electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal and electrical characteristic values respectively corresponding to at least three logic levels of the amplified first modulated signal;

generating a second modulated signal by adjusting at least one of the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal, based on the adjustment signal; and

amplifying power of the second modulated signal to output an amplified second modulated signal.

11. The signal transmitting method of claim 10, wherein the generating the second modulated signal comprises adjusting the at least one of the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal such that a ratio of differences between each of the electrical characteristic values respectively corresponding to the at least three logic levels of the amplified first modulated signal is being same as a ratio of differences between each of the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal, based on the adjustment signal.

12. The signal transmitting method of claim 10, further comprising detecting the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal,

wherein the adjustment signal is generated based on the detected electrical characteristic values.

13. The signal transmitting method of claim 10, wherein the electrical characteristic values respectively corresponding to the at least three logic levels of the first modulated signal are previously stored before the adjustment signal is generated, and

wherein the adjustment signal is generated based on the stored electrical characteristic values.

14. The signal transmitting method of claim 13, further comprising updating at least one of the stored electrical characteristic values based on at least one of the adjustment signal and the second modulated signal.

15. The signal transmitting method of claim 10, further comprising detecting the electrical characteristic values respectively corresponding to the at least three logic levels of the amplified first modulated signal,

wherein the adjustment signal is generated based on the detected electrical characteristic values.