Millimeter-Wave System for High Data Rate Indoor Communications

This paper presents the realization of a wireless Gigabit Ethernet communication system operating in the 60 GHz band. The system architecture uses a single carrier modulation. A differential encoded binary phase shift keying modulation and a differential demodulation scheme are adopted for the intermediate frequency blocks. The baseband blocks use Reed- Solomon RS (255, 239) coding and decoding for channel forward error correction (FEC). First results of bit error rate (BER) measurements at 875 Mbps, without channel coding, are presented for different antennas.Comment: 5 page

Toward a Gigabit Wireless Communications System

This paper presents the design and the realization of a hybrid wireless Gigabit Ethernet indoor communications system operating at 60 GHz. As the 60 GHz radio link operates only in a single-room configuration, an additional Radio over Fiber (RoF) link is used to ensure the communications within all the rooms of a residential environment. The system uses low complexity baseband processing modules. A byte synchronization technique is designed to provide a high value of the preamble detection probability and a very small value of the false detection probability. Conventional RS (255, 239) encoder and decoder are used for channel forward error correction (FEC). The FEC parameters are determined by the tradeoff between higher coding gain and hardware complexity. The results of bit error rate measurements at 875 Mbps are presented for various antennas configurations

60 GHz High Data Rate Wireless Communication System

This paper presents the design and the realization of a 60 GHz wireless Gigabit Ethernet communication system. A differential encoded binary phase shift keying modulation (DBPSK) and differential demodulation schemes are adopted for the IF blocks. The Gigabit Ethernet interface allows a high speed transfer of multimedia files via a 60 GHz wireless link. First measurement results are shown for 875 Mbps data rate.Comment: 5 pages

A low Complexity Wireless Gigabit Ethernet IFoF 60 GHz H/W Platform and Issues

6 pagesInternational audienceThis paper proposes a complete IFoF system architecture derived from simplified IEEE802.15.3c PHY layer proposal to successfully ensure near 1 Gbps on the air interface. The system architecture utilizes low complexity baseband processing modules. The byte/frame synchronization technique is designed to provide a high value of preamble detection probability and a very small value of the false detection probability. Conventional Reed-Solomon RS (255, 239) coding is used for Channel Forward Error Correction (FEC). Good communication link quality and Bit Error Rate (BER) results at 875 Mbps are achieved with directional antennas

Performance analysis of OFDM-IM scheme under STO and CFO

In this letter, performance analysis of orthogonal frequency division multiplexing with index modulation (OFDM-IM) is presented in term of bit error rate (BERs). The analysis considers its performance under two impairments, symbol time offset (STO) and carrier frequency offset (CFO) in frequency-selective fading channel. As orthogonal multicarrier system, OFDM-IM is subject to both inter-symbol interference (ISI) and inter-carrier interference (ICI) in a frequency-selective fading channel. OFDM-IM is a new multicarrier communication system, where the active subcarriers indices are used to carry additional bits of information. In general, in the previous existing works, OFDM-IM are evaluated only for near-ideal communication scenarios by only incorporating the CFO factor. In this work, the OFDM-IM performance is investigated and compared with conventional OFDM in the presence of two impairments, STO and CFO. Simulation results show that OFDM-IM outperforms the conventional OFDM with the presence of STO and CFO, especially at high SNR areas

Distributed space time block coding in asynchronous cooperative relay networks

The design and analysis of various distributed space time block coding schemes for asynchronous cooperative relay networks is considered in this thesis. Rayleigh frequency flat fading channels are assumed to model the links in the networks, and interference suppression techniques together with an orthogonal frequency division multiplexing type transmission approach are employed to mitigate the synchronization errors at the destination node induced by the different delays through the relay nodes. Closed-loop space time block coding is first considered in the context of decode-and-forward (regenerative) networks. In particular, quasi orthogonal and extended orthogonal coding techniques are employed for transmission from four relay nodes and parallel interference cancellation detection is exploited to mitigate synchronization errors. Availability of a direct link between the source and destination nodes is studied, and a new Alamouti space time block coding technique with parallel interference cancellation detection which does not require such a direct link connection and employs two relay nodes is proposed. Outer coding is then added to gain further improvement in end-to-end performance and amplify-and-forward (non regenerative) type networks together with distributed space time coding are considered to reduce relay node complexity. Novel detection schemes are then proposed for decode-and-forward networks with closed-loop extended orthogonal coding which reduce the computational complexity of the parallel interference cancellation. Both sub-optimum and near-optimum detectors are presented for relay nodes with single or dual antennas. End-to-end bit error rate simulations confirm the potential of the approaches and their ability to mitigate synchronization errors. A relay selection approach is also formulated which maximizes spatial diversity gain and attains robustness to timing errors. Finally, a new closed-loop distributed extended orthogonal space time block coding solution for amplify-and-forward type networks which minimizes the number of feedback bits by using a cyclic rotation phase is presented. This approach utilizes an orthogonal frequency division multiplexing type transmission structure with a cyclic prefix to mitigate synchronization errors. End-to-end bit error performance evaluations verify the efficacy of the scheme and its success in overcoming synchronization errors

Security and Privacy in Dynamic Spectrum Access: Challenges and Solutions

abstract: Dynamic spectrum access (DSA) has great potential to address worldwide spectrum shortage by enhancing spectrum efficiency. It allows unlicensed secondary users to access the under-utilized spectrum when the primary users are not transmitting. On the other hand, the open wireless medium subjects DSA systems to various security and privacy issues, which might hinder the practical deployment. This dissertation consists of two parts to discuss the potential challenges and solutions. The first part consists of three chapters, with a focus on secondary-user authentication. Chapter One gives an overview of the challenges and existing solutions in spectrum-misuse detection. Chapter Two presents SpecGuard, the first crowdsourced spectrum-misuse detection framework for DSA systems. In SpecGuard, three novel schemes are proposed for embedding and detecting a spectrum permit at the physical layer. Chapter Three proposes SafeDSA, a novel PHY-based scheme utilizing temporal features for authenticating secondary users. In SafeDSA, the secondary user embeds his spectrum authorization into the cyclic prefix of each physical-layer symbol, which can be detected and authenticated by a verifier. The second part also consists of three chapters, with a focus on crowdsourced spectrum sensing (CSS) with privacy consideration. CSS allows a spectrum sensing provider (SSP) to outsource the spectrum sensing to distributed mobile users. Without strong incentives and location-privacy protection in place, however, mobile users are reluctant to act as crowdsourcing workers for spectrum-sensing tasks. Chapter Four gives an overview of the challenges and existing solutions. Chapter Five presents PriCSS, where the SSP selects participants based on the exponential mechanism such that the participants' sensing cost, associated with their locations, are privacy-preserved. Chapter Six further proposes DPSense, a framework that allows the honest-but-curious SSP to select mobile users for executing spatiotemporal spectrum-sensing tasks without violating the location privacy of mobile users. By collecting perturbed location traces with differential privacy guarantee from participants, the SSP assigns spectrum-sensing tasks to participants with the consideration of both spatial and temporal factors. Through theoretical analysis and simulations, the efficacy and effectiveness of the proposed schemes are validated.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201