DEVICE AND METHOD FOR DETERMINING CHANNEL EQUALIZATION AND RECEPTION DATA OF RECEIVER FOR PACKET COMMUNICATION

• US 20160337148A1
• Filed: 12/17/2014
• Published: 11/17/2016
• Est. Priority Date: 12/19/2013
• Status: Active Grant

• Current Assignee: Korea Institute Of Ocean Science & Technology
• Original Assignee: Korea Institute Of Ocean Science & Technology
• Inventors: YUN, Chang Ho, KIM, Seung Geun, LIM, Yong Kon, PARK, Jong Won
• Granted Patent: US 9,954,697 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 25/03 Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
• CPC Class Codes: H04L 25/03019 adaptive, i.e. capable of adjustment during data reception
• CPC Class Codes: H04L 27/2697 in combination with other modulation techniques

Abstract

Provided is an apparatus for equalizing a channel and determining reception data of a packet communication receiver. The apparatus includes: an input interface unit which receives a reception sample string of a packet having a midamble and location information of the midamble; a sample dividing unit which divides the reception sample string into a first sub sample string and a second sub string stream using the location information of the midamble; and a channel equalizing unit which performs channel equalization on the first sub sample string and the second sub sample string, respectively, using a channel equalizing algorithm of the channel equalizer.

Claims

1. An apparatus for equalizing a channel and determining reception data of a packet communication receiver, the apparatus comprising:

an input interface unit which receives a reception sample string of a packet having a midamble and location information of the midamble;

a sample dividing unit which divides the reception sample string into a first sub sample string and a second sub string stream using the location information of the midamble; and

a channel equalizing unit which performs channel equalization on the first sub sample string and the second sub sample string, respectively, using a channel equalizing algorithm of the channel equalizer.

2. The apparatus according to claim 1, wherein when the reception sample string is divided, the sample dividing unit divides the reception sample string so as to superimpose the midamble.

3. The apparatus according to claim 1, wherein in the first sub sample string, a symbol string is arranged in the order of data 1 and the midamble and in the second sub sample string, a symbol string is arranged in the order to the midamble and data 2.

4. The apparatus according to claim 3, wherein the channel equalizing unit rearranges the order of the first sub sample string in a reverse order to change the arrangement of the symbol string in the order of a reversely arranged midamble and reversely arranged data 1, trains a filter coefficient of the channel equalizer using the reversely arranged reference midamble symbol string as a training signal and performs the channel equalization on the first sub sample string through the filter coefficient using the reversely arranged first sub sample string as an input reception signal of the channel equalizing algorithm of the channel equalizer.

5. The apparatus according to claim 4, wherein the channel equalizing unit defines a midamble binary data string as a first symbol S(0)=(1+j*0), defines a symbol string generated in accordance with a symbol mapping method of π

/4-DQPSK modulation as a reference midamble symbol string, defines the generated reference midamble symbol string which is rearranged in a reverse order as a reversely arranged reference midamble symbol string, and uses the reference midamble symbol string or the reversely arranged reference midamble symbol string as a training signal of the channel equalizer.

6. The apparatus according to claim 3, wherein the channel equalizing unit uses a correctly arranged reference midamble symbol string as a training signal to train a filter coefficient of the channel equalizer, and performs the channel equalization on the second sub sample string through the filter coefficient using the second sub sample string as an input reception signal of a channel equalizing algorithm of the channel equalizer.

7. The apparatus according to claim 3, wherein the channel equalizing unit considers that the first sub sample string is virtually rearranged in a reverse order and uses the reversely arranged reference midamble as a training signal to train the filter coefficient of the channel equalizer and performs the channel equalization on the first sub sample string through the filter coefficient using the first sub sample string as an input reception signal of the channel equalizing algorithm of the channel equalizer.

8. The apparatus according to claim 7, further comprising:

a determining unit which determines a symbol which is the closest to an output symbol of the channel equalizer in a corresponding symbol section among four candidate symbols of a constellation set of a π

/4 DQPSK signal as a reception symbol in the corresponding symbol section, after the symbol section of the training signal to use the determined symbol as a training signal.

9. The apparatus according to claim 7, further comprising:

a determining unit which determines the reception symbol, based on signs of a real part and an imaginary part of an output signal of a filter of the channel equalizer, for a symbol section having one constellation of a constellation set of the π

/4 DQPSK signal, and determines the reception symbol based on a comparison result of absolute values of the real part and the imaginary part of the output signal of the filter of the channel equalizer, for the symbol section having another constellation of the constellation set

10. The apparatus according to claim 1, wherein as the channel equalizing algorithm, any one of a minimum mean square (LMS) algorithm, a recursive least square (RLS) algorithm, and a variable step-size (VSS) algorithm is selectively used.

11. The apparatus according to claim 3, further comprising:

a reception data determining unit which uses a last symbol of the reversely arranged midamble of the output symbol string of the channel equalizer by the reversely arranged first sub sample string as a reference symbol of differential demodulation for determining a transmission symbol in the data 1 part and sequentially performs differential demodulation on the reversely arranged subsequent output symbol string of the channel equalizer of the data 1 part to determine transmission data.

12. The apparatus according to claim 3, further comprising:

a reception data determining unit which uses a symbol corresponding to the last symbol of the reference midamble of the output symbol string of the channel equalizer by the second sub sample string to a symbol by binary data of data 2 as a reference symbol of differential demodulation for determining a transmission symbol, in the data 2 part and performs differential demodulation on the correctly arranged subsequent output symbol string of the channel equalizer of the data 2 part to determine the transmission data.

13. The apparatus according to claim 1, wherein the packet is sampled N (N is a natural number) times for every symbol.

14. A method for equalizing a channel and determining reception data of a packet communication receiver, the method comprising:

receiving a reception sample string of a packet having a midamble and location information of the midamble;

dividing the reception sample string into a first sub sample string and a second sub string stream using the location information of the midamble; and

performing channel equalization on the first sub sample string and the second sub sample string, respectively, using a channel equalizing algorithm of the channel equalizer.

15. The method according to claim 14, wherein the dividing includes:

dividing the reception sample string so as to superimpose the midamble.

16. The method according to claim 14, wherein in the first sub sample string, a symbol string is arranged in the order of data 1 and the midamble and in the second sub sample string, a symbol string is arranged in the order to the midamble and data 2.

17. The method according to claim 16, wherein the performing of channel equalization includes:

rearranging the order of the first sub sample string in a reverse order to change the arrangement of the symbol string in the order of a reversely arranged midamble and reversely arranged data 1;

training a filter coefficient of the channel equalizer using the reversely arranged reference midamble symbol string as a training signal; and

performing the channel equalization on the reversely arranged first sub sample string through the filter coefficient using the reversely arranged first sub sample string as an input reception signal of the channel equalizing algorithm of the channel equalizer.

18. The method according to claim 17, wherein the performing of channel equalization includes:

defining a midamble binary data string as a first symbol S(0)=(1+j*0), defining a symbol string generated in accordance with a symbol mapping method of π

/4-DQPSK modulation as a reference midamble symbol string, defining the generated reference midamble symbol string which is rearranged in a reverse order as a reversely arranged reference midamble symbol string, and using the reference midamble symbol string or the reversely arranged reference midamble symbol string as a training signal of the channel equalizer.

19. The method according to claim 16, wherein the performing of channel equalization includes:

training the filter coefficient of the channel equalizer using the correctly arranged reference midamble symbol string as a training signal; and

performing the channel equalization on the second sub sample string through the filter coefficient using the second sub sample string as an input reception signal of a channel equalizing algorithm of the channel equalizer.

20. The method according to claim 16, wherein the performing of channel equalization includes:

considering that the first sub sample string is virtually rearranged in a reverse order;

training a filter coefficient of the channel equalizer using the reversely arranged reference midamble symbol string as a training signal; and

performing the channel equalization on the virtually reversely arranged first sub sample string through the filter coefficient using the first sub sample string as an input reception signal of the channel equalizing algorithm of the channel equalizer.

21. The method according to claim 20, further comprising:

determining a symbol which is the closest to an output symbol of the channel equalizer in a corresponding symbol section among four candidate symbols of a constellation set of a π

/4 DQPSK signal, as a reception symbol in the corresponding symbol section, after the symbol section of the training signal, to use the determined symbol as a training signal.

22. The method according to claim 20, further comprising:

determining the reception symbol, based on signs of a real part and an imaginary part of an output signal of a filter of the channel equalizer, for a symbol section having one constellation of the constellation set of the π

/4 DQPSK signal; and

determining the reception symbol based on a comparison result of absolute values of the real part and the imaginary part of the output signal of the filter of the channel equalizer, for the symbol section having another constellation of the constellation set.

23. The method according to claim 16, further comprising:

using a last symbol of the reversely arranged midamble of the output symbol string of the channel equalizer by the reversely arranged first sub sample string as a reference symbol of differential demodulation for determining a transmission symbol in the data 1 part; and

performing differential demodulation on the reversely arranged subsequent output symbol string of the channel equalizer of the data 1 part to determine transmission data.

24. The method according to claim 16, further comprising:

using a symbol corresponding to the last symbol of the reference midamble of the output symbol string of the channel equalizer by the second sub sample string to a symbol by binary data of data 2 as a reference symbol of differential demodulation for determining a transmission symbol, in the data 2 part; and

sequentially performing differential demodulation on the correctly arranged subsequent output symbol string of the channel equalizer of the data 2 part to determine the transmission data.