A METHOD AND SYSTEM USING TERNARY SEQUENCES FOR SIMULTANEOUS TRANSMISSION TO COHERENT AND NON-COHERENT RECIEVERS

• US 20160261440A1
• Filed: 10/21/2014
• Published: 09/08/2016
• Est. Priority Date: 10/29/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: PS, Chandrashekhar Thejaswi, JOS, Sujit, BYNAM, Kiran, HONG, Young Jun, PARK, Chang Soon, CHOUDHARY, Manoj
• Granted Patent: US 9,887,861 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 1/709 Correlator structure
• CPC Class Codes: H04B 1/71637 Receiver aspects H04B1/7183 takes precedence
• CPC Class Codes: H04L 25/03312 Arrangements specific to the provision of output signals
• CPC Class Codes: H04L 25/03834 using pulse shaping
• CPC Class Codes: H04L 25/4923 using ternary codes H04L25/4927 takes precedence
• CPC Class Codes: H04L 27/04 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The present invention describes a method and system for simultaneous transmission of data to coherent and non-coherent receivers. The method at the transmitter includes retrieving a base ternary sequence having a pre-defined length, obtaining one or more ternary sequences corresponding to data to be transmitted and transmitting the obtained one or more ternary sequences by the transmitter. The method steps at the receiver includes receiving one or more ternary sequences corresponding to the data transmitted, demodulating each of the received ternary sequences by correlating with all cyclic shifts of the base ternary sequence by the receiver if the receiver is a coherent receiver, demodulating each of the received ternary sequences by correlating with all cyclic shifts of the absolute of the base ternary sequence by the receiver if the receiver is a non-coherent receiver and detecting the transmitted data based on the cyclic shifts corresponding to maximum correlation values.

Claims

1. A method of transmitting data comprising:

retrieving a base ternary sequence having a pre-defined length;

obtaining one or more ternary sequences corresponding to the data to be transmitted from the base ternary sequence; and

transmitting the obtained one or more ternary sequences by the transmitter.

2. The method as claimed in claim 1, wherein the data is in binary form.

3. The method as claimed in claim 1, wherein obtaining one or more ternary sequences corresponding to data to be transmitted from the base ternary sequence comprises:

dividing the data to be transmitted into one or more data-symbols having a pre-defined length; and

mapping each of the data-symbols to the ternary sequence obtained by providing a cyclic shift to the base ternary sequence, wherein the number of said cyclic shifts is determined based on one to one mapping.

4. The method as claimed in claim 1, further comprising:

generating the base ternary sequence having a pre-defined length; and

storing the base ternary sequence in a memory.

5. The method as claimed in claim 4, wherein generating the base ternary sequence comprising:

selecting a seed sequence of pre-defined length, wherein the seed sequence is one of an m-sequence and complement of an m-sequence;

generating a perfect ternary sequence from the seed sequence if weight of the seed sequence is a perfect square;

generating a near perfect ternary sequence from the seed sequence if the weight of the seed sequence is different from a perfect square; and

inserting a pre-defined value in a pre-defined location of one of the perfect ternary sequence and the near perfect ternary sequence for generating the base ternary sequence.

6. The method as claimed in claim 5, wherein generating a perfect ternary sequence from the seed sequence if weight of the seed sequence is a perfect square comprises:

obtaining a preferred pair of the m-sequence from the seed sequence;

obtaining the correlation sequence of the preferred pair, wherein the correlation sequence is obtained as the cross correlation function between the two sequences of the preferred pair;

obtaining an offset correlation sequence from the corresponding correlation sequence; and

generating the perfect ternary sequence based on the offset correlation sequence.

7. The method as claimed in claim 6, wherein obtaining the preferred pair of m-sequence from the seed sequence comprising:

selecting the seed sequence as a first in-sequence of the preferred pair; and

obtaining a second m-sequence of the preferred pair, wherein the second sequence is pre-defined decimation of the first sequence.

8. The method as claimed in claim 5, wherein generating a near perfect ternary sequence from the seed sequence if weight of the seed sequence is different from a perfect square comprises:

obtaining one or more candidate sequences by inverting value of one or more non-zero positions in the seed sequence for a pre-defined ratio; and

selecting a sequence out of the candidate sequences based on the least value of mean squared autocorrelation coefficient (MSAC) as the near perfect ternary sequence.

9. The method as claimed in claim 5, wherein the pre-defined location for inserting a pre-defined value in one of the perfect ternary sequence and the near perfect ternary sequence for generating the base ternary sequence is the location corresponding to least MSAC value across all possible locations.

10. The method as claimed in claim 5, wherein the pre-defined value inserted in one of the perfect ternary sequence and the near perfect ternary sequence is the value “

0”

, if the seed-sequence is an m-sequence; and

the pre-defined value inserted in one of the perfect ternary sequence and the near perfect ternary sequence is value “

1”

if the seed-sequence is complement of an m-sequence.

11. A method of receiving data transmitted from one or more transmitter comprising:

receiving one or more ternary sequences transmitted from the one or more transmitter by a receiver;

demodulating the received one or more ternary sequences using a base ternary sequence; and

detecting the data transmitted from the one or more transmitter.

12. The method as claimed in claim 11, wherein the one or more ternary sequences corresponds to one or more data-symbols having a pre-defined length.

13. The method as claimed in claim 12, wherein one or more data-symbols constitutes the data transmitted from one or more transmitters.

14. The method as claimed in claim 11, wherein demodulating the received one or more ternary sequences using a base ternary sequence comprising:

demodulating each of the received ternary sequence by correlating the received ternary sequence with all cyclic shifts of the base ternary sequence by the receiver if the receiver is a coherent receiver;

demodulating each of the received ternary sequence by correlating the received ternary sequence with all cyclic shifts of the absolute of the base ternary sequence by the receiver if the receiver is a non-coherent receiver.

15. The method as claimed in claim 11, wherein detecting the data transmitted from the one or more transmitter comprising:

identifying the single cyclic shift that corresponds to maximum correlation value among all cyclic shifts ; and

retrieving each of the data-symbol from the said single cyclic shift by mapping back the said single cyclic shift to the data-symbol using the inverse of one to one mapping.

16. The method as claimed in claim 11, further comprising:

generating the base ternary sequence having a pre-defined length; and

storing the base ternary sequence in a memory.

17. The method as claimed in claim 16, wherein generating the base ternary sequence comprising:

selecting a seed sequence of pre-defined length, wherein the seed sequence is one of an m-sequence and complement of an m-sequence;

generating a perfect ternary sequence from the seed sequence if weight of the seed sequence is a perfect square;

generating a near perfect ternary sequence from the seed sequence if the weight of the seed sequence is different from a perfect square; and

inserting a pre-defined value in a pre-defined location of one of the perfect ternary sequence and the near perfect ternary sequence for generating the base ternary sequence.

18. The method as claimed in claim 17, wherein generating a perfect ternary sequence from the seed sequence if weight of the seed sequence is a perfect square comprises:

obtaining a preferred pair of the m-sequence from the seed sequence;

obtaining the correlation sequence of the preferred pair, wherein the correlation sequence obtained as the cross correlation function between the two sequences of the preferred pair;

obtaining an offset correlation sequence from the corresponding correlation sequence; and

generating the perfect ternary sequence based on the offset correlation sequence.

19. The method as claimed in claim 17, wherein obtaining the preferred pair of m-sequence using the seed sequence comprising:

selecting the seed sequence as a first m-sequence of the preferred pair; and

obtaining a second m-sequence of the preferred pair, wherein the second sequence is pre-defined decimation of the first sequence.

20. The method as claimed in claim 17, wherein generating a near perfect ternary sequence from the seed sequence if weight of the seed sequence is different from a perfect square comprises:

obtaining one or more candidate sequences by inverting value of one or more non-zero positions in the seed sequence for a pre-defined ratio; and

selecting at least one sequence out of the candidate sequences based on the least value of mean squared autocorrelation coefficient (MSAC) as the near perfect ternary sequence.

21. The method as claimed in claim 17, wherein the pre-defined location for inserting a pre-defined value in one of the perfect ternary sequence and the near perfect ternary sequence for generating the base ternary sequence is the location corresponding to least MSAC value across all possible locations.

22. The method as claimed in claim 17, wherein the pre-defined value inserted in one of the perfect ternary sequence and the near perfect ternary sequence is the value “

0”

, if the seed-sequence is an m-sequence; and

the pre-defined value inserted in one of the perfect ternary sequence and the near perfect ternary sequence is value “

1”

if the seed-sequence is complement of an m-sequence.

23. A transmitter comprises:

a data input module;

a transmitting module;

a symbol generating module couple with the data input module for adapted for generating one or more symbols based on input data; and

a ternary sequence generating module coupled with the symbol generating module,

a base ternary sequence retrieving module and a cyclic shift generating module, wherein the base ternary sequence retrieving module retrieves one or more base ternary sequence corresponding to the generated symbols; and

the cyclic shift generating module is adapted for generating cyclic shift in the base ternary sequence based on the generated symbol.

24. A base ternary sequence generating module comprises:

a seed sequence selection module adapted for selecting the seed sequence as a first sequence of the preferred pair; and

selecting a second sequence of the preferred pair , wherein the second sequence is pre-defined decimation of the first sequence,

a pre-defined value insertion module.

25. The base ternary sequence generating module as claimed in claim 24, wherein the perfect ternary sequence generation module is adapted for generating a perfect ternary sequence from the seed sequence if the seed sequence is an m-sequence, where the generation of perfect ternary sequence comprises of:

obtaining a preferred pair of the m-sequence from the seed sequence;

obtaining the correlation sequence of the preferred pair, wherein the correlation sequence obtained as the cross correlation function between the two sequences of the preferred pair;

obtaining an offset correlation sequence from the corresponding correlation sequence; and

generating the perfect ternary sequence based on the offset correlation sequence.

26. The base ternary sequence generating module as claimed in claim 24, wherein the near perfect ternary sequence generation module is adapted for generating a near perfect ternary sequence from the seed sequence if the seed sequence is complement of m-sequence, where the generation of perfect ternary sequence comprises of:

obtaining one or more candidate sequences by inverting value of one or more positions having unity weight in the seed sequence for a pre-defined ratio; and

selecting at least one sequence out of the candidate sequences based on the least value of mean squared autocorrelation coefficient (MSAC) as the near perfect ternary sequence.

27. The base ternary sequence generating module as claimed in claim 26, wherein the pre-defined value insertion module adapted for inserting a pre-defined value in one of the perfect ternary sequence and the near perfect ternary sequence to generate the base ternary sequence.

28. A receiver comprising:

a signal receiving module for receiving a signal transmitted from a transmitter;

a demodulating module coupled with a sample sequence input module and the signal receiving module, wherein the demodulating module demodulates the received signal correlating one or more ternary sequence input from the ternary sequence input module with the received signal; and

a symbol detection module is adapted for detecting one or more transmitted data-symbols based on the sequence of maximum correlation corresponding to the demodulated ternary sequence.