Behnam Kamali - Academia.edu (original) (raw)

Papers by Behnam Kamali

AeroMACS, 2018

This chapter provides a brief overview of IEEE 802.16e and its later version IEEE 802.16‐2009 as ... more This chapter provides a brief overview of IEEE 802.16e and its later version IEEE 802.16‐2009 as well as IEEE 802.16j‐2009 standards. These are the parts of IEEE 802.16 standards that are of interest for the study of AeroMACS networks. Mobile WiMAX technology, driven from IEEE 802.16e standards, is reviewed with the objective of providing technical background information for AeroMACS networks. WiMAX Forum's recent release on system profiles and certification profiles is also discussed. The IEEE‐802.16 standard is a large suite of wireless broadband standards composed and authored by the IEEE standard groups. The WiMAX network reference model (NRM) is a logical representation of the network architecture. The NRM identifies functional entities and reference points (RPs) over which interoperability is achieved between functional entities. Multicast and broadcast services (MCBCS), as opposed to point‐to‐point unicast features, refer to downlink point‐to‐multipoint transmission of mu...

Optics Communications, 2015

An orthogonal frequency-division multiplexing access (OFDMA) based visible light communication (V... more An orthogonal frequency-division multiplexing access (OFDMA) based visible light communication (VLC) system is proposed in this paper. The architecture of the proposed system is divided into several VLC cells, which is defined in this paper. The deployment and upgrade of the system involve only simple combination of the VLC cells. Hence it is economically advantageous. To guarantee smooth communication, nearly equal data rate is provided at every location within the system with no concern on the system scale. The user location monitor strategy is also discussed to solve the region division issues. The characteristics of the proposed system are analyzed in detail in this paper. A one-dimensional experiment was demonstrated with 13.6 Mb/s data rate.

2011 Integrated Communications, Navigation, and Surveillance Conference Proceedings, 2011

A new aviation-specific transmission technology based on the WiMAX (Worldwide Interoperability fo... more A new aviation-specific transmission technology based on the WiMAX (Worldwide Interoperability for Microwave Access) IEEE 802.16e-based standard; over a newly available C-band allocation (5091-5150 MHz), has been recently recommended for the airport surface wireless communications network now known as Aeronautical Mobile Airport Communications System (AeroMACS). The proposed standards will be used to support fixed and mobile ground to ground applications and services. It has been established that no technical obstacle exists that would prevent the application of WiMAX networks to AeroMACS. In this article WiMAX networks and some of their salient features are briefly reviewed. The challenges of broadband radio communications through airport surface channels are discussed. A major concern about deployment of AeroMACS over the 5091-5150 MHz band is interference to co-allocated applications such as the Mobile Satellite Service (MSS) feeder link. This limits the power levels that are allowed for AeroMACS networks. We propose an investigation into the feasibility of the application of IEEE 802.16j Amendment (relay-based multi-hop network) to AeroMACS. The potential benefits of multihop relay configuration for AeroMACS networks are identified. Perhaps the most relevant benefit of the multihop relay configuration to AeroMACS is the flexible and cost effective radio range extension that it provides for airport areas shadowed by large constructions and natural obstacles without raising the required network power levels.

Some bounds on the required number of parity check symbols for burst error correction are discuss... more Some bounds on the required number of parity check symbols for burst error correction are discussed. Equations determining burst error correction capabilities of Reed-Solomon (RS) codes constructed over Galois fields of characteristic two are presented. Tables providing burst error correction capabilities of RS codes constructed over GF(256) and GF(64) are provided. Some applications of RS codes in mobile communications are covered, in particular the selection of the (63,47) RS codes for Cellular Digital Packet Data (CDPD) networks is explained. One legitimate concern regarding the application of RS codes in mobile communications is the computational complexity of the RS codes standard decoding method. Three alternative decoding techniques, suitable for RS codes with low error correcting capability are described

2014 IEEE Aerospace Conference, 2014

The Aeronautical Mobile Airport Communications System (AeroMACS) has progressed from concept thro... more The Aeronautical Mobile Airport Communications System (AeroMACS) has progressed from concept through prototype development, testing, and standards development and is now poised for the first operational deployments at nine US airports by the Federal Aviation Administration. These initial deployments will support fixed applications. Mobile applications providing connectivity to and from aircraft and ground-based vehicles on the airport surface will occur at some point in the future. Given that many fixed applications are possible for AeroMACS, it is necessary to now consider whether the existing capacity of AeroMACS will be reached even before the mobile applications are ready to be added, since AeroMACS is constrained by both available bandwidth and transmit power limitations. This paper describes some concepts that may be applied to improve the future capacity of AeroMACS, with a particular emphasis on gains that can be derived from the addition of IEEE 802.16j multihop relays to the AeroMACS standard, where a significant analysis effort has been undertaken.

1994 IEEE GLOBECOM. Communications: The Global Bridge

ABSTRACT The standard Berlekamp-Massey (1965, 1969) iterative algorithm, although the most common... more ABSTRACT The standard Berlekamp-Massey (1965, 1969) iterative algorithm, although the most commonly used decoding method for Reed-Solomon (RS) codes, is computationally complex. A novel decoding technique that combines error trapping decoding and the Berlekamp-Massey algorithm is proposed. It is demonstrated that this decoder maintains the simplicity of the error trapping decoder for the most part. Moreover, it is shown that whenever it is necessary to apply the maximum error correcting capability of the code, only a shortened Berlekamp-Massey algorithm is utilized. Substantial improvement in the decoder throughput relative to that of Berlekamp-Massey decoding is reported. Software simulation is used to verify the theoretical performance analysis

IEEE Transactions on Education, 1994

IEEE Transactions on Broadcasting, 1999

IEEE Transactions on Broadcasting, 2005

In this article we propose the application of Belief Propagation (BP) algorithm as a novel bit-le... more In this article we propose the application of Belief Propagation (BP) algorithm as a novel bit-level soft decision decoding (SDD) technique for Reed-Solomon (RS) codes. A brief tutorial on Belief Propagation algorithm is presented. A central issue in the application of BP algorithm to decoding RS codes is the construction of a sparse parity check matrix for the binary image of the code. It is demonstrated that Vardy's technique may be applied to find a sparse parity check matrix for RS codes. However, this technique is not applicable to all cases. The BP algorithm is applied to two test codes. In one case, simulation models show that the BP algorithm outperforms the hard decision Euclidean decoding by more than 2 dB of additional coding gain. The results with the second test code are not as promising [1].

IEEE Aerospace and Electronic Systems Magazine, 1996

Intelligent Vehicle Highway Systems (IVHS) have generated a new challenge for communications indu... more Intelligent Vehicle Highway Systems (IVHS) have generated a new challenge for communications industries. This is particularly true for mobile communications, since most essential IVHS communications links require wireless and mobile transmission. The IVHS and its major components are described. A generic block diagram for an IVHS network is presented. This block diagram defines the communications requirements for the IVHS network. The complete characterization of communication between the vehicle and the IVHS infrastructure is determined by the system architecture, however, by its very nature, this link is required to be wireless, mobile, and for the most part interactive. A survey of wireless technologies that have been tested, or implemented, and/or considered suitable for IVHS applications are discussed. Examples of operational and/or under development IVHS projects that applies the corresponding wireless technology are also provided.

2007 Integrated Communications, Navigation and Surveillance Conference, 2007

The Aeronautical Mobile Airport Communication Systems (AeroMACS) has already been deployed in nin... more The Aeronautical Mobile Airport Communication Systems (AeroMACS) has already been deployed in nine major US airports. This technology is used to support fixed and mobile ground-to-ground applications and services. In this article it is demonstrated that IEEE 802.16j-amendment-based WiMAX is most feasible for future enhancement of AeroMACS networks. Perhaps the most important benefit of application of multihop relays in AeroMACS is the flexible, power efficient, and cost-effective radio range extension into severely shadowed airport areas. Multihop relay operational modes are discussed. The key concept of “multihop gain,” which explains how multihop relays enable performance enhancement in AeroMACS networks, is introduced. Under a reasonable set of assumptions, multihop gain is quantified in the form of an equation that provides a raw measure of this gain in Decibel.

The unpredictability caused by random fluctuations of the airport radio channel characteristics, ... more The unpredictability caused by random fluctuations of the airport radio channel characteristics, makes the standard approach of using a single modulation scheme that represents an optimum choice under various conditions on an airport surface environment, unrealistic. Same observation maybe made in regards to choosing a channel coding technique. The IEEE 802.16-2009 standard supports a variety of modulation formats and coding schemes. The essence of adaptive modulation coding (AMC) is the selection of appropriate modulation and coding combination to confront the propagation conditions of the airport channel. In this tutorial article, the AeroMACS mandatory modulation schemes, consisting of three square M-ary Quadrature Amplitude Modulation, are characterized. Channel coding process and the mandatory forward error correction scheme, a tail-biting non-systematic non-recursive convolutional code, are briefly described. AMC is the methodology of link adaptation in AeroMACS systems. The r...

2000 Annual Conference Proceedings

The electrical engineering senior capstone laboratory course is meant "to provide the electrical ... more The electrical engineering senior capstone laboratory course is meant "to provide the electrical engineering senior student with additional and varied experiences in creating and designing working electrical/ electronic/ electromechanical systems, from specifications to prototype product". At Mercer University we have structured this course such that in addition to design stipulations, it addresses a number of other EC 2000 requirements, specially, those listed under criterion III; "Program Outcomes and Assessment". In particular, attempts are made to expose the student to a number of important features of engineering profession in the 21 th century. Specifically, three important issues of globalization of engineering practice, the need for lifelong learning, and the role of technical communications skills are addressed in this course. Moreover, the design of an engineering experiment is included in this course. In this article, following a detailed account of the structure of this course, we provide a list of several design projects that have been selected for this course. A sample design project on fabrication and testing of a simple AM radio receiver is described in some detail. Finally, a sample on "Design of an Experiment" is referenced briefly.