A.H.M. Razibul Islam

Simplification of millimeter-wave radio-over-fiber system employing heterodyning of uncorrelated optical carriers and self-homodyning of RF signal at the receiver

A simplified millimeter-wave (mm-wave) radio-over-fiber (RoF) system employing a combination of optical heterodyning in signal generation and radio frequency (RF) self-homodyning in data recovery process is proposed and demonstrated. Three variants of the system are considered in which two independent uncorrelated lasers with a frequency offset equal to the desired mm-wave carrier frequency are used to generate the transmitted signal. Uncorrelated phase noise in the resulting mm-wave signal after photodetection was overcome by using RF self-homodyning in the data recovery process. Theoretical analyses followed by experimental results and simulated characterizations confirm the systems performance. A key advantage of the system is that it avoids the need for high-speed electro-optic and electronic devices operating at the RF carrier frequency at both the central station and base stations.

Multilevel Intensity Modulations for Simplified Full-Duplex Millimeter-Wave Radio-Over-Fiber System for Gigabit Access

Multilevel M-ary amplitude-shift-key (M-ASK) intensity modulation formats have been proposed and experimentally demonstrated in millimeter-wave radio-over-fiber (mm-wave RoF) system. In order to demonstrate multilevel intensity modulation for spectrally efficient implementation, return-to-zero (RZ) and non-RZ (NRZ) implementations for both 4-ASK and 8-ASK modulation formats are utilized in full-duplex RoF link. Hence, for downlink, two different signal generation schemes are utilized in this paper for optical mm-wave generation and transport using optical heterodyning of two unlocked lasers. For uplink, similar RF self-homodyning technique is applied at the base station (BS) to simplify the signal translation process. Theoretical analyses and experimental results using the proposed technique for M-ASK modulation formats confirm the systems performance. Apart from the bandwidth-efficient realization of the proposed schemes, demonstrated full-duplex RoF techniques avoid most of the high-speed electrooptic and RF devices from both the central station (CS) and BSs keeping the optical mm-wave generation, optical transport, and BSs simpler in both directions.

Adjacent Channel Power Ratio of OFDM Signals for Broadband Convergence Networks

In this paper, adjacent channel power ratio (ACPR) of orthogonal frequency division multiplexed (OFDM) system interconnected with radio over fiber (RoF) link at 2.3 GHz WiBro environment were analyzed and simulated at both system ends.

Next Generation Rural Wireless Connectivity Model for Developing Countries

Next generation wireless technology with converged voice and data applications can offer rural connectivity for proper boost in information and communication technology (ICT). In this study, a cost-effective ICT based solution for economic development of rural community in developing countries using appropriate next generation wireless networking technology has been represented. In the target country, Bangladesh, several wireless rural points (WRPs) in a village will be connected to the local server of the village called wireless access point (WAP). Each of several WAPs will be connected to several rural resource servers (RRSs) and thus will form a rural resource network (RRN). Adopting the proposed model with the existing ICT infrastructure of the target country can provide significant economic development therefore for the rural community. A similar implementation in other developing countries can offer a massive success

Simplification of base station and uplink optical transport in millimeter-wave radio-over-fiber system employing RF self-homodyning

A simplified uplink communication scheme for millimeter-wave (mm-wave) radio-over-fiber system employing RF self-homodyning at the base station (BS) is proposed and experimentally demonstrated. The proposed scheme establishes a simple low-speed data transmission from the BS to the central station and simplifies the BS and uplink optical transport by removing most of the required high speed optoelectronic and RF devices.

Provisioning in-house mobility for FTTH customers by incorporating modifications in optical network unit (ONU)

A modified ONU provisioning in-house mobility for FTTH customers is proposed and demonstrated. This scheme, in addition to fixed point access, distributes FTTH services wirelessly, potentially at equal speeds.

PAPR and SFDR of an OFDM-RoF link

This paper presents design tradeoffs between PAPR and SFDR using an RF amplifier in an OFDM-RoF link, depending on number of subcarriers. PAPR degradation of 2 dB for 512 subcarriers showed SFDR gain of 25 dB.Hz2/3.

Next Generation Converged Connectivity Model for Rural Business Opportunities in Developing Countries

In this paper, a cost-effective next generation converged network connectivity model has been proposed for the rural business opportunities in developing countries with an optical fiber backboned wireless rural point (WRP)-rural resource network (RRN) approach.

Recent progresses in Gigabit wireless access using millimetre-wave RoFs

Millimetre-wave radio-over-fibre (RoF) systems are widely considered as a disruptive technology for Gigabit/s wireless access applications. This paper reviews recent progresses in the simplification of generation, transport and detection of optically modulated millimetre-wave signal that can offer Gb/s wireless access at potentially low-costs. The review highlights the introduction of unlocked optical heterodyning in photodetection and direct conversion receiver in demodulation that potentially overcome the key hurdles to realize low-cost RoF systems.

In-house seamless and transparent internet on the move through cordless access to FTTH

The recent proliferation of modern portable devices and applications demands to deploy in-house high-speed Internet on the move. Millimeter-wave (mm-wave) wireless with its inherent multi-Gb/s capacities is seen as an alternative to fiber-to-the-home (FTTH) that has benchmarked the access of future Internet through fiber. This paper investigates a suitable approach to interface FTTH with mm-waves that enables in-house transparent and seamless access to Internet on the move through cordless access to FTTH. In such case, in addition to fixed point access, in-house optical network unit (ONU) establishes mm-wave cordless communications without any translation of FTTH data or modulation format.