Shannon Channel Capacity Theorem Research Articles

Adaptive Resource Optimization For Cognitive Radio Networks

In cognitive radio network, the spectrum sensing finds either the channel is occupied or idle, the problem is assigning the unused channels of the primary user (PU) to the secondary users in an efficient manner is most challenging issue. In this work, we investigates the above issue and proposed an adaptive resource allocation to the secondary users in terms of channel allocation and power allocation. The proposed work intelligently handles both frequency and space efficiently without affecting the quality of service (QoS) of the primary user. We considered both underlay and overlay spectrum access, based on that resource allocation is carried out in an efficient manner. The maximum transmitted data rate of the secondary user (SU) obtained is 225Kbps determined by using Shannon channel capacity theorem. The proposed work also shows the effectiveness of the simulation in terms of energy efficiency up to 8.25 x 105 bits/Joule.

HUMIDITY EFFECT TO 5G PERFORMANCES UNDER PALEMBANG CHANNEL MODEL AT 28 GHZ

The telecommunication has a tremendous improvement in terms of data rates and bandwidth requiring sufficient frequency allocation and wideband spectrum availability. The millimeter-wave frequency band is one of the solution to these requirements, however communications in this band is facing new challenges on the climate effect to the channel propagation In this paper, we propose a 5G channel model considering the effect of humidity based on the characteristic of the natural environment of Palembang city. The channel model is represented by power levels and delay called a Power Delay Profile (PDP and is derived based on a series of computer simulations using parameters of nature in Palembang. The 5G channel model is important to further derive the outage performance to be used as the theoretical performance of 5G in Palembang since the the Shannon Channel Capacity Theorem is involved in the derivation. We conduct a series of computer simulations to evaluate the validity of the proposed channel model and its characteristics. We found that humidity affect to the performances, where high humidity makes the performances of outage and BER slightly worse, although the effect may be ignored for some applications. The results of this paper are expected to be the references for the development and implementation of 5G Networks especially at the mm-Wave band in Palembang.

Shannon Meets Fick on the Microfluidic Channel: Diffusion Limit to Sum Broadcast Capacity for Molecular Communication.

Molecular communication (MC) over a microfluidic channel with flow is investigated based on Shannon's channel capacity theorem and Fick's laws of diffusion. Specifically, the sum capacity for MC between a single transmitter and multiple receivers (broadcast MC) is studied. The transmitter communicates by using different types of signaling molecules with each receiver over the microfluidic channel. The transmitted molecules propagate through microfluidic channel until reaching the corresponding receiver. Although the use of different types of molecules provides orthogonal signaling, the sum broadcast capacity may not scale with the number of the receivers due to physics of the propagation (interplay between convection and diffusion based on distance). In this paper, the performance of broadcast MC on a microfluidic chip is characterized by studying the physical geometry of the microfluidic channel and leveraging the information theory. The convergence of the sum capacity for microfluidic broadcast channel is analytically investigated based on the physical system parameters with respect to the increasing number of molecular receivers. The analysis presented here can be useful to predict the achievable information rate in microfluidic interconnects for the biochemical computation and microfluidic multi-sample assays.

A Lower Bound for the Hardware Complexity of FIR Filters

Shannon's channel capacity theorem states that in a communication channel the available power budget (SNR) dictates the maximum realizable data rate. A relevant question for FIR filters then is this: Given a hardware budget, can we similarly define a general upper bound on the performance capabilities of a realizable FIR filter? And if yes, how close are the hardware complexities of existing FIR filter designs in relation to such performance limitations? Herein, we investigate such questions and we present a practical approach to derive a lower bound for the minimal hardware budget required for a practical FIR filter realization of a given set of target filter specifications. We believe this to be an important insight for fully understanding the design complexities of FIR filters and for properly managing their power consumption expectations.

Double-space-cooperation method for increasing channel capacity

Shannon channel capacity theorem poses highest bit-rate of error free transmission over additive white Gaussian noise channel. In addition, he proved that there exists channel code that can theoretically achieve the channel capacity. Indeed fortunately, the latter researchers found some practical channel codes approaching the channel capacity with insignificant losses of spectral efficiency under ignorable bit error rate (BER). The authors note, in general, that bits of the channel codes are not independent of each other in code space. Further, we note that the modulated symbols are not independent among them, as well, in Euclidean Space. By exploiting a usage of the dependencies jointly to signal design, we can transmit two independent signal streams through an additive white Gaussian channel and separate them in Euclidean space at the receiver. The capacity of this approach is found larger than that of Shannon capacity in the same channel assumptions. The numerical results confirm the theoretical procedures.

A Unified Carnot Thermodynamic and Shannon Channel Capacity Information-Theoretic Energy Efficiency Analysis

In this paper we employ the Shannon channel capacity theorem and classical thermodynamic Carnot's Law to derive the kT ln 2 minimum energy dissipation per bit for a communications channel. We then extend the analysis, incorporating forward error correction (FEC) to show an asymptotic energy efficiency approach to the Carnot/Shannon limit. For the first time, we derive a generalized version of the Shannon channel capacity theorem which embraces non-Gaussian noise statistics. Finally, we apply the theory to different telecommunications technologies, thus offering commonality of absolute energy efficiency assessment.

Calculation of Channel Capacity Considering the Effect of Different Seasons for Higher Altitude Platform System

This paper presents effect of the weather impairments on a high altitude platform (HAP) broadband wireless communication system. It is shown that attenuation due to oxygen, water vapor, fog, cloud, and rain has significant effect on a radio link which is operating in a millimeter frequency range. Channel capacity is calculated for different seasons using Shannon's channel capacity theorem. The location of HAP is taken to be Delhi (India). Further, it is considered that a user and the HAP platform are stationary.

Effect of urban-site and vegetation on channel capacity in higher altitude platform communication system

Communication services using higher altitude platforms have highlighted a need for estimating the effect of local obstructions on radio wave link. Vegetation and buildings are the major factors responsible for attenuation. The authors have calculated the radio wave attenuation because of vegetation and buildings. Here, the authors have used the fitted radio international telecommunication union model to calculate the vegetation attenuation. The attenuation because of buildings is calculated for an urban-site (residential area of Netaji Subhas Institute of Technology, NSIT, New Delhi, India) using geometrical optics and a uniform theory of diffraction. Further, channel capacity is calculated for vegetation and urban-site environment using Shannon's channel capacity theorem.

A Discussion About Some of the Principles/Practices of Wireless Communication Under a Maxwellian Framework

There has been a plethora of papers dealing with wireless communication that use techniques, which when viewed from the perspective of a Maxwellian framework raise more questions than they answer. By Maxwellian framework we imply not only the relevance of electromagnetics in studying communication systems but also the proper interpretation of an ensemble processing in mathematical physics which was first introduced by Maxwell to study the behavior of an aggregate of molecules rather than the property of individuals. Initially, most of the modern signal processing techniques was developed for scalar acoustic problems. However, with the advent of wireless, these same techniques are being applied to the vector electromagnetics problem, which is fundamentally different in concept with respect to the scalar acoustic problem. The objective is to discuss some of these concerns associated with some of the current modeling methodologies particularly related to propagation modeling and antenna diversity. A goal is to initiate a dialog about the scientific merits of these new applications. One of the points to be made is that an incorrect use of probability theory can often lead to erroneous conclusions that directly contradict the principles of physics. A few examples are presented to initiate this dialog, mainly the applicability of scalar techniques to the vector wireless problem, including a proper interpretation of the Shannon channel capacity theorem. A methodology is also presented to illustrate how a simple multiple-input-multiple-output system can be based on the principles of reciprocity. Integration of the electromagnetic principles in some of the current methodologies of signal processing and communications theory may lead to a better system

Sequence logos, machine/channel capacity, Maxwell's demon, and molecular computers: a review of the theory of molecular machines

Living cells contain many molecules which can make simple decisions, such as whether to bind to a particular nucleotide sequence or not. A theory describing the practical limits of these molecular machines is reviewed. Level 0 theory uses Shannon's information theory to study genetic control systems. Level 1 theory uses Shannon's channel capacity theorem to explain how these biological molecules are able to make their decisions precisely in the face of the thermal maelstrom surrounding them. Level 2 theory shows how the Second Law of Thermodynamics defines the exact extent of the choices available to a molecular machine when it dissipates a given amount of energy. Even the famous Maxwell demon must obey this result. The theory also has implications for designing molecular computers.

Communication Efficiency Comparison of Several Communication Systems

Of increasing importance in communication systems, particularly those required for data transmission from space craft, is the minimization of the total transmitted energy required to transmit a given amount of data. Modulation systems can be compared on the basis of a figure of merit defined as the ratio of energy required per bit transmitted in the presence of a given noise spectral density. Using this criterion, several families of communication systems are compared in this article, including AM, FM, FM/FM, and orthogonal matched filter communication systems. It is found that the orthogonal systems uniformly require less power to transmit at a given information rate than other systems and approach closely the theoretical limit established by Shannon's channel capacity theorem.