Attractive features of time-hopping spread-spectrum multiple-access systems employing impulse signal technology are outlined, and emerging design issues are described. Performance of such communications systems in terms of achievable transmission rate and multiple-access capability are estimated for both analog and digital data modulation formats under ideal multiple-access channel conditions.

In Ad hoc networks, malicious nodes can enter in radio transmission range on the routing path and disrupt network activity. Therefore, protecting from intrusion of malicious node and enhance data security is an important issue on Ad hoc networks. In this study, we provide a path hopping method based on reverse AODV (R-AODV). By reverse AODV, source node builds multipath to destination and adapt...

General Packet radio service (GPRS) is designed for transmitting packet data and supposed to take its radio resource from the pool of unused channels by GSM voice services. Obviously, the introduction of GPRS has impact on the voice services. In this paper, we present a method to calculate the outage probability of the GSM-GPRS network for both the non-frequency hopping and the frequency hoppi...

In this paper, we study the significance of aperiodicity in the pitch-perception of expressive voices such as Noh voice and laughter signals. The excitation source characteristics in the production of these signals is represented in terms of a sequence of impulses. The impulse sequence is derived from the acoustic signal using a modified zero-frequency filtering method. The time intervals betwe...

We describe a generation-oriented workbench for the Performance Grammar (PG) formalism, highlighting the treatment of certain word order and movement constraints in Dutch and German. PG enables a simple and uniform treatment of a heterogeneous collection of linear order phenomena in the domain of verb constructions (variably known as Cross-serial Dependencies, Verb Raising, Clause Union, Extrap...

Mobile holes in an antiferromagnetic insulator form a slowly fluctuating array of quasi one-dimensional metallic stripes, which induce a spin gap or pseudogap in the intervening Mott-insulating regions. The mobile holes on an individual stripe acquire a spin gap via pair hopping between the stripe and its environment; i.e. via a magnetic analog of the usual superconducting proximity effect. Thi...

In this paper a technique is offered for improving the efficiency of communication. The prime objective of any Communication Technique is not only to make the communication clear, efficient and noise free but also to make the communication well secured from its interception from unauthorized users in both commercial as well as in defense communication. For this purpose nowadays the most commonl...

ABSTRA CT— The use of spread spectrum time hopping in combination with pulse position modulation for multiple access communications is studied. The multiple access performance is described in terms of the number of users supported by the system for a given bit error rate and bit transmission rate. Expressions for the maximum number of users and maximum transmission capacity in bits per second a...

General packet radio service (GPRS) is designed for transmitting packet data and supposed to take its radio resource from the pool of channels unused by GSM voice services. Obviously, the introduction of GPRS affects on the voice services. In this paper the outage probability of non-frequency hopping and frequency hopping systems with different frequency reuse factor has been calculated in ord...

This paper describes a minimalist hopping robot that can perform basic exploration tasks on Mars or other moderate gravity bodies. We show that a single actuator can control the vehicle’s jumping and steering operations, as well as the panning of an on-board camera. Our novel thrusting linkage also leads to good system efficiency. The inherent minimalism of our hopping paradigm offers interesti...