Fan Liu’s Post

How to design optimal ISAC precoder when random data payload signals are exploited for sensing? In this new TSP paper, we proposed a dedicated precoding design for random ISAC signals for a point-to-point MIMO ISAC system. The key idea here is to define and optimize an ergodic sensing performance metric, i.e., the estimation error averaged over random signals, which could be regarded as the sensing duality of the ergodic communication rate defined for MIMO fading channels. More details can be found at: https://lnkd.in/gRjSwxx8 #6G #ISAC #RandomSignals #MIMO

Check out this popular #openaccess article from the IEEE Photonics Journal, titled "Dynamic Control of Distal Spatial Mode Pattern Output From Multimode Fiber Using Integrated Coherent Network." Impact Statement from Authors (Dan YI , Xuetong Zhou, Hon Tsang): "We implemented an integrated mesh of Mach Zehnder Interferometer at the transmitter to demonstrate control of the distal end mode field distribution to ensure low coupling losses in the receiver?s MWGC.The coherent MZI network can be dynamically controlled to produce the desired mode pattern at the distal end of the FMF to enable low loss coupling at the distal end. This enables the practical deployment of mode division multiplexing with MWGC without needing manual control of fiber orientation." Read more to explore the full impact: https://lnkd.in/e2-PRfj2 #IEEEPhotonics #ResearchInnovation

Downlink electromagnetic field (EMF) exposure assessment studies for 6G mobile communication systems are in the early research phase. I am excited to share our latest publication in IEEE Transactions on Electromagnetic Compatibility, where we assess the EMF exposure from 6G D-MIMO deployment scenarios in an industrial indoor environment based on the metrics incident power density (IPD) and specific absorption rate (SAR). For comparison, EMF exposure from a massive MIMO (mMIMO) deployment scenario is also assessed in the same environment. The simulated exposure at ground level is well below the limits specified in the international EMF exposure guidelines considering realistic output power levels for both D-MIMO and mMIMO scenarios. Great collaborative effort together with Bo Xu. #EMF #6G #Ericsson

How do we multiplex eMBB and URLLC uplink traffic over a wireless communication link provided by a Reconfigurable Intelligent Surface (RIS)? Moreover, how can we do this efficiently by having only eMBB Channel State Information (CSI)? We addressed this challenging question in a paper that is out now in IEEE Communications Letters, the last one of my PhD! In the proposed strategy, a hybrid RIS with minimal signal processing capability detects the traffic type from received uplink symbols. Then, depending on the detected type, the RIS switches over two pre-computed configurations for its elements, carefully optimized using solely eMBB CSI to provide adequate Quality of Service for eMBB or URLLC traffic. I appreciate the opportunity to work on this project with Victor Croisfelt, Radosław Kotaba, Taufik Abrao, and Petar Popovski. IEEE Xplore: https://lnkd.in/dyzsmND4 #wireless #ris #ieee

This letter introduced a novel #optical #DACs (#oDAC) parallelizing a pair of optimized 2-segment MZMs, remarkably fed by 4 uncoupled NRZ signals. Based on a pair of IQ-nested new oDACs, the resulting DAC-less QAM #Transmitters (#Tx) is fed by 8 uncoupled NRZ drivers. The energy efficiency, photonic efficiency and resolution of the flexible oDAC and QAM Tx are at their utmost. ---- Moshe Nazarathy, Dr. Ioannis Tomkos More details can be found at this link: https://lnkd.in/eBQJs8KZ

This work focuses on the minimization of interference from the neighboring cells through optimal resource allocation and power optimization. #Rate-#splitting #multiple #access (#RSMA) technique is employed where the message to be transmitted is divided into two parts. Two modes for resource allocation are formulated which aims to maximize the throughput under certain interference constraints. The radius of coverage expression is derived for switching of modes to take place. #Successive #interference #cancelation (#SIC) is introduced as a power constraint which enhances the overall performance of the network. Subsequently, Lagrange’s dual-optimization method is utilized for optimizing the #device-#to-#device (#D2D) transmit power and also lowering the computational complexity of the overall network. ---- Dr. Subhra Sankha Sarma, Ranjay Hazra, Pratik Goswami More details can be found at this link: https://lnkd.in/gFJU3pD3

In this paper, they consider the deployment of #ISAC in a #full-#duplex #cell-#free (#FD-#CF) multi-input #multi-#output (#MIMO) system that is aided by a #reconfigurable #intelligent #surface (#RIS). To overcome the performance limitations of a single #ISAC #base #station (#BS), we consider multiple FD #access #points (#APs) that simultaneously perform target detection and #multi-#user #uplink (#UL) communication, assisted by a #RIS. They aim to maximize the weighted sum of the output radar and communication #signal-#to-#interference-#plus-#noise #ratios (#SINRs) by jointly designing the radar and communication receive beamformers, UL transmission powers, joint #downlink (#DL) sensing #beamformers, and RIS reflection coefficients. The total UL, DL power budgets, and the RIS phase shift unit-modulus constraints are considered to guarantee the balance between sensing and communication requirements. The resulting problem is non-convex and rather formidable to solve. Nonetheless, an efficient solution to this problem is developed based on alternating optimization, which utilizes #majorization-#minimization (#MM), #fractional #programming (#FP), and the penalty method. Simulations demonstrate the effectiveness of the proposed solution and the advantages of deploying #RIS to assist #integrated #cooperative #sensing and #communication (#ICSAC) in #FD-#CF #MIMO systems. ----Ahmed Abdelaziz Salem, Ph.D. @Mahmoud Albreem; @Khawla Alnajjar; Saeed Abdallah Mohamed Saad More details can be found at this link: https://lnkd.in/g5DiBVgJ

In this paper, they present a #comprehensive #foundation for the theory and practice of pilot-based carrier phase synchronization of #OFDM symbols in the presence of phase noise. The system covers #phase #noise added in both the transmitter and receiver together with a #frequency-#selective #channel. A novel, #low-#complexity, #phase #noise #estimation method is presented, and they show that it is close to optimal over a wide dynamic range of #phase #noise. Additionally, a method for approximating the phase noise over the #OFDM #symbol using principal component analysis is proposed, where the number of parameters to estimate can be significantly reduced with minimal impact on performance. ----Bjorn Gavert Mikael Coldrey Thomas Eriksson More details can be found at this link: https://lnkd.in/gTEce5Mb

The joint #radar-#communication (#RadCom) concept has been continuously gaining interest due to the possibility of integrating radar sensing and communication functionalities in the same radio frequency hardware platform. Besides a number of challenges in terms of hardware design and signal processing, the choice of suitable modulation schemes plays a significant role in driving the performance of RadCom systems. This article presents an overview of state-of-the-art modulation schemes for #RadCom systems, namely, chirp sequence, phase-modulated continuous wave, orthogonal frequency-division multiplexing, and orthogonal chirp-division multiplexing. ----Lucas Giroto de Oliveira, Benjamin Nuß More details can be found at this link: https://lnkd.in/g-X8HUpq

We are proud to announce the publication of our paper "" which was partially funded by our project! Congratulations Ana Flávia dos Reis, Bruno Sens Chang, Yahia Medjadi, Glauber Brante and Faouzi Bader Check https://lnkd.in/drRauQ_R for more information Abstract: Orthogonal Time Frequency Space (OTFS) is a promising modulation scheme that works in the delay-Doppler (DD) domain, offering resistance to frequency selective fading and time-varying channels. Thus, OTFS channel estimation assumes great significance for successful transmission. Typically, it requires allocating pilots in the DD domain, which often results in an increase in the peak-to-average power ratio (PAPR) and high complexity to detect the received signal. In response to these issues, we present a solution that estimates the channel in the time-frequency (TF) domain. In addition, although several works in the literature present solutions for OTFS channel estimation, few consider the presence of high-power amplifiers (HPAs) and explain the impact of nonlinear effects on channel estimation and system performance. Starting from channel estimation based on preambles and pilots in the TF domain, we present a solution capable of obtaining reliable channel estimation using a long short-term memory (LSTM) network in highly selective channel conditions, effectively compensating for nonlinearities in signal reception. Our results validate the effectiveness of the proposed solution, highlighting its potential to improve the performance and robustness of OTFS communication systems in real scenarios with nonlinear HPA effects. #ChannelEstimation, #LSTM, #OTFS, #HPADistortions, #VehicularCommunication