Cooperative spectrum sensing in cognitive radio networks: A survey

This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

The Transmission Control Protocol.

With the rapid deployment of new wireless devices and applications, the last decade has witnessed a growing demand for wireless radio spectrum. However, the fixed spectrum assignment policy becomes a bottleneck for more efficient spectrum utilization, under which a great portion of the licensed spectrum is severely under-utilized. The inefficient usage of the limited spectrum resources urges the spectrum regulatory bodies to review their policy and start to seek for innovative communication technology that can exploit the wireless spectrum in a more intelligent and flexible way. The concept of cognitive radio is proposed to address the issue of spectrum efficiency and has been receiving an increasing attention in recent years, since it equips wireless users the capability to optimally adapt their operating parameters according to the interactions with the surrounding radio environment. There have been many significant developments in the past few years on cognitive radios. This paper surveys recent advances in research related to cognitive radios. The fundamentals of cognitive radio technology, architecture of a cognitive radio network and its applications are first introduced. The existing works in spectrum sensing are reviewed, and important issues in dynamic spectrum allocation and sharing are investigated in detail.

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Advances in cognitive radio networks: A survey

Intelligent reflecting surface (IRS) is an enabling technology to engineer the radio signal propagation in wireless networks. By smartly tuning the signal reflection via a large number of low-cost passive reflecting elements, IRS is capable of dynamically altering wireless channels to enhance the communication performance. It is thus expected that the new IRS-aided hybrid wireless network comprising both active and passive components will be highly promising to achieve a sustainable capacity growth cost-effectively in the future. Despite its great potential, IRS faces new challenges to be efficiently integrated into wireless networks, such as reflection optimization, channel estimation, and deployment from communication design perspectives. In this paper, we provide a tutorial overview of IRS-aided wireless communications to address the above issues, and elaborate its reflection and channel models, hardware architecture and practical constraints, as well as various appealing applications in wireless networks. Moreover, we highlight important directions worthy of further investigation in future work.

Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial

The functional architecture and basic design principles for Multi-Granularity OXC (MG-OXC) networks have been introduced in Chapter 2. This chapter provides two dynamic algorithms for solving the problem of routing and wavelength assignment with tunnel allocation, namely Dynamic Tunnel Allocation and Capacity-Balanced Static Tunnel Allocation schemes. In addition to the routing algorithms, we will present their performance evaluation in two sample networks.

Routing and Wavelength Assignment with Multi-Granularity OXCs

A cross-layer framework of interplay between multiple description coding (MDC) at the source and layered modulation using superposition coding (SPC) at the channel has recently been proposed as an effective approach to mitigate the vicious effects due to multi-user diversity and fast Rayleigh fading in wireless video broadcast/multicast. However, there has not been a rigorous and general end-to-end distortion analysis to determine if and when such interplay between the protection code (such as MDC) in the upper layer and the multi-resolution modulation by way of SPC in PHY/MAC layer for transmitting successively refined information can lead to a better end-to-end distortion performance than other possibilities. The paper provides a comprehensive information theoretical analysis on the end-to-end distortion. Mathematical proofs are derived to confirm the advantages and conditions of such cross-layer systems to always give the better distortion performance. Numerical analysis is conducted to verify the mathematical conclusions while unveiling some interesting observations.

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Coded wireless video broadcast/ multicast: a cross-layer framework and end-to-end distortion analysis

Under a given modulation scheme and a target BER (bit error rate) requirement, it is difficult to increase the number of bits transmitted in each symbol (i.e., the rate), since this generally requires a significant increase of transmit power. In this paper, we study how to increase the rate in multiuser multiple-input multiple-output (MU-MIMO) broadcast channels using only bit and power loading, without requiring additional transmit power. To solve this challenging problem, our approach is to carry out a joint design of bit loading and power allocation over all streams, and meanwhile take user and stream selection into account. Specifically, we maximize the total number of bits per symbol (rather than the Shannon capacity) over all selected streams, under a target BER constraint for each stream and a constant total transmit power constraint. To enable flexible user and stream selection as well as achieving a high total rate, we consider OSDM (orthogonal space division multiplexing) rather than BD (block diagonalization) based MU-MIMO broadcast channels. Numerical results show that our proposed joint bit and power loading with OSDM user and stream selection is effective in increasing the total transmission rate without consuming additional resources.

Joint bit and power loading with user and stream selection in OSDM MU-MIMO broadcast channels

Network survivability against component failure is an important issue in WDM (Wavelength Division Multiplexing) optical networks. This includes failure detection, localization and isolation (i.e. protection or restoration). In this paper, we focus on link-based failure localization and protection in WDM networks. Different preconfigured optical structures including simple, non-simple cycles and trails are discussed, and their applications in fast link failure localization and protection are studied. We generate solutions using ILPs (Integer Linear Programs) and analyze the pros and cons of each structure. Our analysis shows that simple cycles can be regarded as a special case of non-simple cycles, and both simple and non-simple cycles are special cases of trails. Therefore, trails provide the most general and flexible structure to generate the best solutions.

Preconfigured structures for survivable WDM networks

With deployment of 5G and emerging 6G networks, the demand of wireless communication for transmission capacity as well as the transmission security in consumer electronics is increasing. Reconfigurable intelligent surface (RIS) has shown a great potential in physical layer security (PLS) due to its enabling technology to engineer the radio signal prorogation. In this paper, we study PLS problems of RIS-assisted wireless communication system, where the RIS is deployed to aid pair of the transmitter (Alice) and receiver (Bob) under the active jamming (Jammer) and eavesdropper (Eve) attack. Different from traditional RIS schemes, our proposed scheme divides the RIS into two parts which not only enhances the legitimate user performance but also suppresses the eavesdropper. Specifically, the location of the jammer is also considered with two different scenarios, i.e., the distance between the jammer and RIS is smaller/greater than that of the one between the transmitter and RIS. Considering the influence of RIS reflection coefficient, path loss and uncertain jammer locations, we analyze the system performance based on the legitimate and eavesdropping channels, providing the upper and lower bounds of achievable received signal-to-noise ratio (SNR) instead of the secrecy outage probability (SOP). In addition, the simulation and asymptotic results reveal the location influence of the interference on the secrecy performance and the superiority of the proposed scheme. 

Pin-Han Ho

Papers

Routing and Wavelength Assignment with Multi-Granularity OXCs

Coded wireless video broadcast/ multicast: a cross-layer framework and end-to-end distortion analysis

Joint bit and power loading with user and stream selection in OSDM MU-MIMO broadcast channels

Preconfigured structures for survivable WDM networks

Optimal RIS Allocations for PLS with Uncertain Jammer and Eavesdropper