Krishna Chandra Roy

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Spectrum scarceness is one of the major challenges that the present world is facing. The efficient use of existing licensed spectrum is becoming most critical as growing demand of the radio spectrum. Different researches show that the use of licensed are not utilized inefficiently. It has been also shown that primary user does not use more than 70% of the(More)
We know that the radio electromagnetic spectrum is a natural resource and efficient usage of the inadequate natural resource is one of the greatest challenges of today’s wireless communication system just like petrol, coal and water. The efficient use of the available licensed spectrum is becoming more and more critical with increasing demand and usage of(More)
Nowadays, It has been shown that spectrum scarcity increased due to tremendous growth of new players in wireless base system by the evolution of the radio communication. Resent survey found that there are many areas of the radio spectrum that are occupied by authorized user/primary user (PU), which are not fully utilized. Cognitive radios (CR) prove to next(More)
In cognitive radio networks, the secondary user network are allowed to utilize the underutilized frequency bands of primary user network on non-interfering basis. To achieve this task, the secondary users (SU) are required to sense the RF environment, and once the primary user (PU) is found to be active, the SU have to give up the channel within certain(More)
The paper present a novel multi-band compact antenna designed on the theory of fractal geometry. The antenna is fabricated on a FR4 substrate. The performance of the proposed antenna design is analyzed and the results are compared with the simulations using IE-3D tool. The relevant antenna performance parameters of the proposed design viz. resonant bands,(More)
In some earlier work, MPC and PRPC are believed to offer higher throughput and better error correction capability at high bit error rate (BER) and large packet size only. An analysis was performed to substantiate this claim of higher throughput and better error correction capability in high as well as in low bit error rate (BER) for large and medium packet(More)
Round Robin scheduling algorithm is the most often used scheduling algorithm in timesharing systems as it is fair to all processes and is starvation free. But along with these advantages it suffers from some drawbacks such as more number of context switches, long waiting and long turnaround time. The main objective of this paper is to improve existing round(More)
Ultrasound strain imaging has great importance as tumor or cancerous tissues are much stiffer than normal tissues. Estimations of strain calculating the time delays between consecutive ultrasound echo signals are common approaches in quasi-static elastography. Because of the ill posed nature of strain images, the ultrasound strain estimation still remains(More)
In this paper we are proposing a new concept in MAC layer protocol design for Cognitive radio by combining information held by physical layer and MAC layer with analytical engine based on knowledge based reasoning approach. In the proposed system a cross layer information regarding signal to interference and noise ratio (SINR) and received power are(More)
Detection techniques based on the absence of any knowledge of the received carrier phase are referred to as non-coherent detection techniques. The optimum receiver under such a scenario is well known to be a structure that incorporates a form of square-law detection. This demodulation through M matched filters, where each one corresponds to the transmitted(More)