Nima Khajehnouri

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Wireless location refers to the geographic coordinates of a mobile subscriber in cellular or wireless local area network (WLAN) environments. Wireless location finding has emerged as an essential public safety feature of cellular systems in response to an order issued by the Federal Communications Commission (FCC) in 1996. The FCC mandate aims to solve a(More)
A fundamental task in a wireless sensor network is to broadcast some measured data from an origin sensor to a destination sensor. Since the sensors are typically small, power limited, and low cost, they are only able to broadcast low-power signals. As a result, the propagation loss from the origin to the destination nodes can attenuate the signals beyond(More)
In this paper we propose a multi-sensor relay strategy that achieves path-loss saving and improved power efficiency. In the proposed distributed scheme, the relay sensors do not need to share information about the received signals. An mean-square error design is pursued and the performance is shown to improve as the number of relay sensors (N) increases.(More)
Location finding for CDMA subscribers using an antenna m a y at the base station is studied in this paper. Two methods are considered for radio location that are based on time of arrival (TOA) and angle of arrival (AOA) measurements. For TOA estimates, a maximum likelihood algorithm and a practical structure are proposed when an antenna array is available.(More)
This paper proposes a globally distributed synchronization algorithm for wireless sensor networks. In the proposed scheme, there is a master node that controls the network synchronization and the other sensors periodically broadcast synchronization pulses; they also monitor different frequency channels in an effort to overcome the effect of channel fading.
Overlapping multipath propagation is one of the main sources of mobile-positioning errors, especially in fast channel fading situations. In this paper we present a technique for detecting the existence of overlapping fading multipath components. Such information is vital for accurate resolving of overlapping multipath components as well as avoiding(More)
Abstnrer-Location finding for CDMA subscribers using an antenna army at the base station and deploying multiple base stations is studied in this paper. ' b o metbods are considered for radio location: measured time-of-arrival (TOA) and angle-of-anival (AOA), and algorithms to estimate them are presented. The estimated TOA and AOA fmm different base stations(More)
Phase noise causes significant degradation in the performance of Orthogonal Frequency Division Multiplexing (OFDM) based wireless communication systems. In the proposed compensation scheme, the communication between the transmitter and receiver blocks consists of two stages. In the first stage, block-type pilot symbols are transmitted and the channel(More)