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In order to avoid transmission collisions in Mobile Ad hoc Networks (MANETs), a reliable and ecient Medium Access Control (MAC) protocol is needed. Vehicular MANETs (VANETs) have vehicles as network nodes and their main characteristics are the high mobility and speed. Active Safety applications for VANETs need to establish reliable communications with(More)
—Nowadays, researchers show more and more interests to Vehicular Ad hoc NETworks (VANETs), which are a specific instance of Mobile Ad hoc NETworks (MANETs) where nodes are vehicles. In VANETs, vehicles have no energy resource constraint which could extend coverage and network lifetime, but have a high mobility patterns that cause frequent and fast topology(More)
Wireless vehicular communications are attracting more and more interests for applied research in industries. Most of the efforts are spent in deploying Vehicular Mobile AdHoc Networks (VANETs) for applications such as active safety and Internet services. This paper addresses routing problem in VANETs for applications related to comfort and infotainment for(More)
We propose a RAKE structured receiver with the pulseshape MF replaced with another FIR filter, and the sparse propagation channel MF by another sparse filter. We compare different choices for the design of the FIR filter and the sparse filter and their adaptation. We model the channel as an autoregressive first-order process over slot periods, with(More)
Efficient dissemination of messages in a Vehicular Ad Hoc Network (VANET) still face many challenges in the current research scenario. This paper addresses the problem of redundant forwarding of messages that occur during broad- cast and proposes an adaptive forwarding mechanism which controls the amount of redundant messages thereby improving message(More)
The conventional receiver for DS-CDMA communications is the RAKE receiver. The RAKE receiver is a matched filter, matched to the operations of spreading, pulse shape filtering and channel filtering. Such a matched filter maximizes the Signal-to-Interference-plus-Noise Ratio (SINR) at its output if the interference plus noise is white. This may be(More)
The deployment of third generation CDMA-based wireless systems foresees a loading fraction that is smaller than one, i.e. the number of users per cell is scheduled to be significantly less than the spreading factor to attain an acceptable performance. This means that a base station can set apart a subset of the codes, the excess codes, that it will not use.(More)
— In DS-CDMA communications, the conventional receiver is the RAKE receiver. In the downlink (base station to mobile) signalling with cell-dependent scrambling, orthogonal codes and a common channel for all the users, this receiver does not maximize the Signal-to-Interference-plus-Noise Ratio (SINR) at its output. Another receiver, with the same structure(More)
In this paper we consider the estimation of mobile channels that are modeled as autoregressive processes with a bandwidth commensurate with the Doppler spread. Pilot based estimation leads to brute FIR channel estimates on a slot by slot basis. These estimates are then refined by Wiener filtering across slots that performs the optimal compromise between(More)