In multi-access wireless communication systems, power control and adaptive modulation are two important means to increase spectral efficiency, combat with time varying fading environment, and reduce co-channel interference. In this paper, the overall transmitted power is minimized by using adaptive MQAM modulation. Each link can select a range of different MQAM modulation according to its curre...

Many algorithms and techniques were proposed to increase the efficiency of Sensor Networks. Due to high restrictions of this kind of networks, where the resources are limited, many factors may affect its work. Theses factors are: System throughput, system delay, and energy. Clustering protocols have been propose to decrease system throughput and system delay, and increase energy saving. In this...

This paper presents a solution of implementing the add-compare-select (ACS) unit of a Viterbi decoder by parallel hardware for high data rates. For a fixed processing speed of the given hardware it allows a linear increase in throughput rate by a linear increase in hardware complexity. Thus arbitrary throughput rates can be achieved by linearly adding more parallel hardware elements. A systolic...

Physical topology of an ad hoc wireless network imposes fundamental limits on its throughput capacity. In this work, we present a network design algorithm for configuring node locations in an 802.11 ad hoc network with the goal of improving the throughput capacity of the network. Given a network configuration (i.e., a mapping of network nodes to physical locations), we establish an inverse prop...

The IEEE 802.15.4 is the standard for Low Rate Wireless Personal Area network (LR-WPAN). It is widely used in many application areas. The standard uses Slotted CSMA/CA mechanism in its contention access period (CAP) for the beacon enabled mode. The protocol has two modes single sensing (SS) and double sensing (DS). The protocol also adopts a binary exponential backoff (BEB) algorithm. In this p...

It is shown that the throughput capacity of wireless ad hoc networks using omni-directional antennas (OMN networks) is significantly decreased with the increased number of nodes. One major reason lies in the interference caused by using omni-directional antennas, which just broadcast radio signal in all directions. Thus, a communication with multiple short-ranged hops is suggested in such netwo...

Background: Persistent hair loss is a dermatological disorder that causes psychological pain and poor quality of life in patients with loss. Hair transplantation or drug-based therapeutics such as minoxidil finasteride have been clinically used to treat Still, they limitations due their several side effects transitory improvement patients. To solve this problem, new drugs recently reported for ...