This paper measures the performance of cooperative spectrum sensing, over Rayleigh fading channel and additive white Gaussian noise, based on softened two-bit hard combination scheme. Two measures based on energy detection are considered including effect of false alarm probability, and effect of number of users. Simulation results show that the detection probability increases with the increase of false alarm probability, number of users, and signal-to-noise-ratio.
This paper focuses on designing, programming and implementing a maze wonderer robot that takes the commands to dictate its direction of motion based on the obstacle avoidance. A program is to be written to give the robot its intelligence. The paper will as well be restricted to a motorized car which will be given the intelligence to be able to navigate through a given maze.
Design of mobile robots has become an increasingly growing trend in the technology of modern times. They are very attractive engineering systems, not only because of many interesting theoretical aspects concerning kinematics, intelligent behavior and autonomy, but also because of applicability in many human activities. A typical example is the line following robot (LFR). In order for a LFR to function effectively, it must demonstrate excellent line tracking control. This is achieved by having accurate and responsive control algorithms as well as high precision color sensor systems. This paper proposes a system to show that good line tracking performance can be achieved with moderately simple digital control algorithms. The platform used is a differentially driven wheeled robot constructed using the Lego Mindstorms components. The simulation models are presented and analyzed using MATLAB Simulink. The main programming environment is the EV3 Software.
The major constraints in the design of Wireless Body Area Network(WBAN) can be attributed to the battery autonomy, need for high data rate services and low interference from the devices operating within the industrial, scientific and medical (ISM) bands. To meet the demand for high data rate services and low power spectral density to avoid ISM band interference, an ultra-wide band(UWB) system based technology has been proposed. This paper focuses on the design and demonstration of an UWB modem to be used in the WBAN applications and the evaluation of its performance in a near-real world scenarios affected by additive white Gaussian noise(AWGN) interference. The modem is tested with different values of signal to noise ratio(SNR). Results show that the performance of the modem degrades as the value of SNR decreases.
Direct sequence spread spectrum (DSSS) communication systems offer significant performance advantages in view of their low probability of intercept, improved performance in multipath fading environments and their ability to avoid interference by spreading the signal over a wide bandwidth hence distributing the power. For the transmitted sequence to be correctly received and demodulated, the spreading sequence used at the receiver should be similar to that employed in the transmitter. This paper utilizes MATLAB Simulink to demonstrate a method of synchronizing the code clock at the receiver with the code clock at the transmitter. This fine alignment process is knownas code tracking.
Turbo coding is a very powerful error correction technique that has made a tremendous impact on channel coding in the past two decades. It outperforms most known coding schemes by achieving near Shannon limit error correction using simple component codes and large interleavers. This paper investigates the turbo coder in detail. It presents a design and a working model of the error correction technique using Simulink, a companion softwareto MATLAB. Finally, graphical and tabular results are presented to show that the designed turbo coder works as expected.
Frequency hopping spread spectrum (FHSS) communication systems offer significant performance advantages in view of their low probability of intercept, improved performance in multipath fading environments and their ability to avoid interference by hopping into low interference frequency channels. For the transmitted sequence to be correctly received and demodulated, the frequency hop sequence used at the receiver should be similar to that employed in the transmitter. Code acquisition infrequency hopping attempts to address this problem by providing a frequency hop pattern at the receiver that is nearly identical to that used at the transmitter. Code acquisition brings the alignment between the transmitter and the receiver hop pattern to at least one hop period. The main objective of this paper is to design and demonstrate a FHSS code acquisition method. The type of channel used is Additive White Gaussian Noise (AWGN).
Rain as a weather phenomenon is one of the things that greatly affects propagation of radio waves. Above 10 GHz, the attenuation brought about by the interaction of the propagating waves and the rain droplets becomes significant for both terrestrial radio links and satellite links. For this reason, rain attenuation models have been developed to aid in planning purposes for network implementation. The models use statistics to predict the attenuation that is caused by specific amount of rain and also the type of rain. This means that different regions will have different levels of attenuation due to the fact that they experience different types and amount of rain. A couple of models exist including the ITU-R, Moupfouma model, Crane attenuation model and other localized models depending on the geographical area that research data collection and extensive analysis has been conducted on and a comprehensive set of values and factors have been determined that can aid in estimation of attenuation due to rain. This paper seeks to provide a viable means by which a transmission engineer can be able to know the attenuation per kilometer due to the various models. This is achieved by designing a software calculator that provides the output of the attenuation per kilometer (dB/Km) while taking an input of rain rate for the different models available. The calculator is based on visual basic platform and works with forms.
A multiple rank modulation (MRM) scheme is proposed that provides better error performance, enhances the data rate and reduces the system demodulation complexity. Multiple input multiple output (MIMO) scheme is a technique that uses several antennas at the transmitter and receiver to minimize error and optimize data speed. MRM is a novel technique that borrows from spatial modulation-MIMO (SM-MIMO) scheme. The basic idea of this scheme involves the transmitter receiving a group of bits and subdividing them into two blocks; rank index block and signal modulation block. The rank index bit block is used to select the rank to be activated and the rank selected contains at least one active transmit antenna (TA). The signal modulation bit block is encoded in a given modulation scheme for transmission. It is then transmitted through the activated rank that contains at least one active TA. The transmitted encoded signal modulation bit block is received through the receive antenna and a receiver. The receiver estimates a rank index and the transmitted symbol from the signal received. The signal modulation bit block is finally decoded. This paper addresses the performance of MRM scheme based on error performance to run cellular fifth generation (5G). We perform and present simulation results of MIMO systems employing MRM scheme to generate bit error rate (BER) of this system.
Wireless Body Area Networks (WBANs) have been developed as the human-body monitoring systems to predict, diagnose, and treat diseases. Since the signal transmission in WBANs takes place in or around the human body the channel fading significantly affects packet error rate and overall network performance. This paper focuses on the design and demonstration of an ultra-wideband (UWB) modem to be used in the WBAN applications, and the evaluation of its performance over Rayleigh fading channel. Results show how the fading channel affects the performance of the system.