Rahulkrishnan Chandrasekharan | National Institute of Technology, Calicut (original) (raw)

Papers by Rahulkrishnan Chandrasekharan

Codebook Excited Linear Prediction (CELP) is one of the most widely used class of speech coder... more Codebook Excited Linear Prediction (CELP) is one of the most widely used class of speech coders which is based on the concept of LPC. The enhancement is that a codebook of different excitation signals is maintained on the encoder and decoder. The encoder finds the most suitable excitation signal sends its index to the decoder which then uses it to reproduce the signal. Hence the name Codebook Excited is given to this coder. There are many variants of CELP that are in use in various applications. Low Delay CELP (LD-CELP) and Algebraic CELP (ACELP) are generally used in internet voice calls and cell phones.

This paper provides an easy way to find the center of incircle circumcircle and excircle of a tr... more This paper provides an easy way to find the center of incircle circumcircle and excircle of a triangle. Please contact the author at sarasuiyer@yahoo.com

In number theory, integer factorization or prime factorization is the decomposition of a composit... more In number theory, integer factorization or prime factorization is the decomposition of a composite number into smaller non-trivial divisors, which when multiplied together equals the original integer. A prime factor can be visualized by understanding Euclid's geometric position. He saw a whole number as a line segment, which has a smallest line segment greater than 1 that can divide equally into it. By the fundamental theorem of arithmetic, every positive integer has a unique prime factorization. However, the fundamental theorem of arithmetic gives no insight into how to obtain an integer's prime factorization; it only guarantees its existence.

A Detailed Business plan about IT Outsourcing in India

An Adaptive noise cancellation system is preferred in applications where there is no prior knowle... more An Adaptive noise cancellation system is preferred in applications where there is no prior knowledge of the signal to be filtered or the noise which corrupts it. Such a case occurs in many military applications. Also noise cancellation is very much required in day-to-day applications such as mobile and other wireless communication systems. Another very important issue in communication systems, especially military, is the security of the data. If the data that is being send is not encrypted in some way then, the enemy or anybody who intercepts the data can access it. Finally compressing the data will allow us to communicate much more information, with the transmission of much less data.

In this project we aim to design and implement using suitable hardware, a communication system that incorporates all of the above requirements .That is, a noisy speech signal is filtered using an adaptive noise cancellation system, which is then compressed using predictive line coding techniques. The compressed data is the encrypted using a suitable private key algorithm and is transmitted in real time. Private key rather than public key is used to encrypt the speech because public key encryption is computationally intensive and transmitting information in real-time will be almost impossible. Currently the encryption of data is not used in mobile communication systems, but it will surely be implemented in the near future, as security issues are becoming a major concern. One of the main challenges is to optimise the processor usage to meet the real time requirements of the system.

Codebook Excited Linear Prediction (CELP) is one of the most widely used class of speech coder... more Codebook Excited Linear Prediction (CELP) is one of the most widely used class of speech coders which is based on the concept of LPC. The enhancement is that a codebook of different excitation signals is maintained on the encoder and decoder. The encoder finds the most suitable excitation signal sends its index to the decoder which then uses it to reproduce the signal. Hence the name Codebook Excited is given to this coder. There are many variants of CELP that are in use in various applications. Low Delay CELP (LD-CELP) and Algebraic CELP (ACELP) are generally used in internet voice calls and cell phones.

This paper provides an easy way to find the center of incircle circumcircle and excircle of a tr... more This paper provides an easy way to find the center of incircle circumcircle and excircle of a triangle. Please contact the author at sarasuiyer@yahoo.com

In number theory, integer factorization or prime factorization is the decomposition of a composit... more In number theory, integer factorization or prime factorization is the decomposition of a composite number into smaller non-trivial divisors, which when multiplied together equals the original integer. A prime factor can be visualized by understanding Euclid's geometric position. He saw a whole number as a line segment, which has a smallest line segment greater than 1 that can divide equally into it. By the fundamental theorem of arithmetic, every positive integer has a unique prime factorization. However, the fundamental theorem of arithmetic gives no insight into how to obtain an integer's prime factorization; it only guarantees its existence.

A Detailed Business plan about IT Outsourcing in India

An Adaptive noise cancellation system is preferred in applications where there is no prior knowle... more An Adaptive noise cancellation system is preferred in applications where there is no prior knowledge of the signal to be filtered or the noise which corrupts it. Such a case occurs in many military applications. Also noise cancellation is very much required in day-to-day applications such as mobile and other wireless communication systems. Another very important issue in communication systems, especially military, is the security of the data. If the data that is being send is not encrypted in some way then, the enemy or anybody who intercepts the data can access it. Finally compressing the data will allow us to communicate much more information, with the transmission of much less data.

In this project we aim to design and implement using suitable hardware, a communication system that incorporates all of the above requirements .That is, a noisy speech signal is filtered using an adaptive noise cancellation system, which is then compressed using predictive line coding techniques. The compressed data is the encrypted using a suitable private key algorithm and is transmitted in real time. Private key rather than public key is used to encrypt the speech because public key encryption is computationally intensive and transmitting information in real-time will be almost impossible. Currently the encryption of data is not used in mobile communication systems, but it will surely be implemented in the near future, as security issues are becoming a major concern. One of the main challenges is to optimise the processor usage to meet the real time requirements of the system.