A Comparative study on Handoff Algorithms for GSM and CDMA Cellular Networks

The GSM, CDMA cellular systems are most trendy 2G and 3G digital cellular telecommunications systems, which is widely used throughout the world. These systems have many advantages such as high security, higher quality of call transmission over the long distances, low transmitted power, and enhanced capacity with more efficient utilization of the frequency spectrum. With these advantages these cellular systems have attracted more subscribers with more attention in the field of mobile communications. One of the most attractive features of cellular system is handoff which is a continuation of an active call when the mobile is moving from one cell to another without disconnecting the call. Usually, continuous service is achieved by efficiently designed handoff algorithms. So, efficient handoff algorithms are necessary for enhancing the capacity and QoS of cellular system. In this paper, the handoff analysis for GSM, CDMA cellular networks are done under various propagation models. Various handoff algorithms of GSM are described and also a novel received signal strength (RSS) based GSM handoff algorithm with adaptive hysteresis is analyzed. CDMA Soft handoff algorithm is analyzed and effective soft handoff parameters are estimated for better performance. The Comparison of handoff algorithms is studied based on results

Modified Kalman Filter for GPS Position Estimation over the Indian Sub Continent

AbstractPosition accuracy is the measure of a system's capability to provide quality estimates, which in turn depends mainly on measurement noise and the type of algorithm employed. Though many positioning algorithms have emerged, due to its exceptional performance in a wide range of real time applications, the Kalman Filter Estimator (KFE) is used often for their implementation. So this paper concentrates in improving its accuracy further while introducing a new observation matrix in its estimation process and succeeds in performing the same. This paper also extends the modified algorithm for GPS receiver position estimation over the Indian subcontinent. Real time data collected from GPS receiver located at IISC, Bangalore (Lat/Lon: 13.010N /77.560E), India is used to evaluate the performance of this developed algorithm called Modified Kalman Filter Estimator (MKFE). GPS Statistical Accuracy Measures (SAM) such as Circular Error Probability (CEP), Spherical Error Probability (SEP) etc. are used for performance evaluation. From the results it is observed that the proposed MKFE has faster convergence rate with high accuracy and is suitable for real time defence applications over the Indian subcontinent

Estimation of GPS User Location Using Linearization Technique and Bancroft Algorithms

This paper describes determination of GPS receiver position using Linearization technique and Bancroft algorithms. The position is determined by obtaining pseudo ranges from eight different GPS satellites. The measured ranges do not represent the true ranges as the signal coming from a GPS satellite will be contaminated by various errors like Ephemeris error; Propagation error in the form of Ionospheric and Tropospheric delays; Satellite and Receiver clock biases with respect to GPS Time (GPST); Multipath error etc. Most of these errors can be estimated accurately and can be accounted for. In this paper some standard mitigation techniques have been applied for the estimation of GPS errors and user position is then determined using the above two technique after making appropriate corrections. GPS data of Chitrakut station available in RINEX (Receiver Independent Exchange) format have been used for this purpos

NEW BACTERIA FORAGING AND PARTICLE SWARM HYBRID ALGORITHM FOR MEDICAL IMAGE COMPRESSION

For perfect diagnosis of brain tumour, it is necessary to identify tumour affected regions in the brain in MRI (Magnetic Resonance Imaging) images effectively and compression of these images for transmission over a communication channel at high speed with better visual quality to the experts. An attempt has been made in this paper for identifying tumour regions with optimal thresholds which are optimized with the proposed Hybrid Bacteria Foraging Optimization Algorithm (BFOA) and Particle Swarm Optimization (PSO) named (HBFOA-PSO) by maximizing the Renyi’s entropy and Kapur’s entropy. BFOA may be trapped into local optimal problem and delay in execution time (convergence time) because of random chemo taxis steps in the procedure of algorithm and to get global solution, a theory of swarming is commenced in the structure of HBFOA-PSO. Effectiveness of this HBFOA-PSO is evaluated on six different MRI images of brain with tumours and proved to be better in Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE) and Fitness Function

AN EFFICIENT IMPLEMENTATION OF TRACKING USING KALMAN FILTER FOR UNDERWATER ROBOT APPLICATION

ABSTRACT The exploration of oceans and sea beds is being made increasingly possible through the development of Autonomous Underwater Vehicles (AUVs). This is an activity that concerns the marine community and it must confront the existence of notable challenges. However, an automatic detecting and tracking system is the first and foremost element for an AUV or an aqueous surveillance network. In this paper a method of Kalman filter was presented to solve the problems of objects track in sonar images. Region of object was extracted by threshold segment and morphology process, and the features of invariant moment and area were analysed. Results show that the method presented has the advantages of good robustness, high accuracy and real-time characteristic, and it is efficient in underwater target track based on sonar images and also suited for the purpose of Obstacle avoidance for the AUV to operate in the constrained underwater environment

Effect of environmental changes on the performance of ILS located at Hyderabad airport

431-434In civil aviation, the existing precision approach (PA) landing system equipment has certain limitations due to ground environment, which affects the performance of the equipment. The effect of changes in the environment conditions surrounding the airport on Instrumental Landing System (ILS) course structure has been presented by comparing the calibrated and measured data at Hyderabad airport (India). The field strength data are acquired using the NORMAC ILS signal field test receiver and compared with the calibration aircraft (AVRO HS-748) data. Performance of the existing ILS is analyzed and the results confirm the effect of environmental changes on the ILS course structure