Objectives

We design algorithms and VLSI implementations that address the challenges of baseband processing in mmWave/Terahertz MIMO systems. We look for solutions that can be implemented efficiently in hardware, taking into account power consumption, throughput, and latency constraints. These challenges include the design of efficient channel estimation, data detection, and precoding methods with the goal of minimizing power consumption and maximizing data-rate.

Approach

Starting with a theoretical formulation of the problem, we use a variety of techniques, such as numerical optimization and approximate algorithms, to come up with efficient, hardware-friendly solutions. We perform extensive simulations to quantify the performance and gains of our algorithms, which we then implement on FPGAs and ASICs in order to demonstrate their efficacy and feasibility. The co-design of algorithms and their corresponding hardware implementations provides the opportunity to maximize throughput, latency, power consumption, and time-to-market.    

Realizing next-generation wireless systems that support spectrally-efficient spatially-multiplexed communication between hundreds of user equipments and a multi-antenna base station is a demanding challenge that requires careful consideration of a large number of aspects. With this in mind, we hold periodic meetings with the rest of the ComSenTer systems teams to share our new ideas and results, to validate and further improve them, to integrate these new ideas in the hardware prototype, and to implemented our results in hardware.

Accomplishments

We have proposed an efficient and low-complexity beamspace-domain channel estimation algorithm called BEACHES, which effectively improves the channel estimates by leveraging the beamspace-domain sparsity of mmWave/THz wireless channels. We have also presented an efficient FPGA implementation that entails low resource utilization and achieves high throughput. We have also proposed the use of quantized approaches to speed up, and alleviate the power consumption, of some of the most critical tasks in wireless communications systems, such as uplink data detection and downlink precoding.

Team Leader

Christoph Studer

Christoph Studer (S’06–M’10) was born in Solothurn, Switzerland on December 25, 1979. He received the M.Sc. and Dr. sc. degrees in electrical engineering from ETH Zürich, Switzerland, in 2005 and 2009, respectively. In 2005, he was a Visiting Researcher with the Smart Antennas Research Group, Information Systems Laboratory, Stanford University, Stanford, CA. From 2006 to 2009, he was a Research Assistant with the Integrated Systems Laboratory (IIS) at ETH Zurich. In 2008, he was a consultant for Celestrius, an ETH-spinoff specialized in the field of MIMO wireless communication. Between 2008 and 2010, he was a postdoctoral researcher at the Communication Technology Laboratory, ETH Zurich, Switzerland. Since 2011, he has been a postdoctoral researcher at the Department of Electrical and Computer Engineering, Rice University, Houston, TX. His research interests include signal processing and the design of VLSI circuits and systems. Dr. Studer was the recipient of an ETH Medal in 2005 and 2011 for his Master’s and his Ph.D. thesis, respectively. He received the Best Student Paper Award of the 2007 Asilomar Conf. on Signals, Systems, and Computers and of the 2008 IEEE Int. Symp. on Circuits and Systems. In 2010, he received (jointly with Dr. Seethaler and Mr. Fateh) the Swisscom and ICTnet Innovations Award.

Publications

Publications

G. Marti, C. Studer, & O. Castaneda (2021, December 9). Beam-Slicing for Jammer Mitigation in mmWave Massive MU-MIMO. IEEE Xplore [Online]. https://ieeexplore.ieee.org/document/9645049.

S. H. Mirfarshbafan, O. F. Castaneda Fernandez, S. Ghajari, A. Molnar, S. Jacobsson, G. Durisi, & C. Studer, “Resolution-Adaptive All-Digital Spatial Equalization for mmWave Massive MU-MIMO,” presented at the 2021 IEEE 22nd International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Lucca, Italy, September 27-30, 2021.

S. Taner & C. Studer (2021, July 14). Optimality of the Discrete Fourier Transform for Beamspace Massive MU-MIMO  Communication. arXiv.org [Online]. Available: https://arxiv.org/abs/2107.06953.

S. Taner, S. H. Mirfarshbafan, & C. Studer (2021, March 8). SMUL-FFT: A Streaming Multiplierless Fast Fourier Transform. IEEE Xplore [Online]. Available: https://ieeexplore.ieee.org/document/9372342.

S. Hadi Mirfarshbafan, S. Taner & C. Studer (2021, March 8). SMUL-FFT: A Streaming Multiplierless Fast Fourier Transform. IEEE Xplore [Online]. https://ieeexplore.ieee.org/document/9372342.

C. Jeon, A. Maleki, & C. Studer (2021, February 25). Mismatched Data Detection in Massive MU-MIMO. arXiv.org [Online]. https://arxiv.org/abs/2007.06491.

A. G. Sanhueza & C. Studer (2021, February 8). Blind SNR Estimation and Nonparametric Channel Denoising in Multi-Antenna mmWave Systems. arXiv.org [Online]. Available: https://arxiv.org/abs/2011.05113.

Z. M. Enciso, S. H. Mirfarshbafan, O. F. C. Fernandez, C. J. Schaefer, C. Studer, & S. Joshi, “Analog vs. Digital Spatial Transforms: A Throughput, Power, and Area Comparison,” presented at the 2020 IEEE 63rd International Midwest Symposium on Circuits and Systems (MWSCAS), Springfield, MA, August 9-12, 2020.

A. G. Sanhueza, R. Ghods, S. H. Mirfarshbafan, & C. Studer, “Sparsity-Adaptive Beamspace Channel Estimation for 1-Bit mmWave Massive MIMO Systems,” presented at the 2020 IEEE 21st International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Atlanta, GA, May 26-29, 2020.

S. H. Mirfarshbafan and C. Studer, “Sparse Beamspace Equalization for Massive Mu-Mimo Mmwave Systems,” presented at the IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Barcelona, Spain, May 14, 2020.

O. Castaneda, S. Jacobsson, G. Durisi, T. Goldstein, & C. Studer, “Soft-Output Finite Alphabet Equalization for mmWave Massive MIMO,” presented at the IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Barcelona, Spain, May 4-8, 2020.

O. F. Castaneda Fernandez, G. Durisi, T. Goldstein, C. Studer, & S. Jacobsson (2020, March 30). High-Bandwidth Spatial Equalization for mmWave Massive MU-MIMO with Processing-In-Memory. IEEE Xplore [Online]. Available: https://ieeexplore.ieee.org/document/9050632.

P. Skrimponis, S. Dutta, M. Mezzavilla, S. Rangan, S. H. Mirfarshbi, C. Studer, J. F. Buckwalter, & M. Rodwell, “Power Consumption Analysis for Mobile MmWave and Sub-THz Receivers,” presented at the 2020 2nd 6G Wireless Summit (6G SUMMIT), Levi, Finland, March 17-20, 2020.

D. Cabric & H. Yan, “DSP Linearization for Millimeter-Wave All-Digital Receiver Array with Low-Resolution ADCs,” presented at the 2019 IEEE 20th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Cannes, France, July 2-5, 2019.

D. Cabric & H. Yan, “Wideband Millimeter-Wave Beam Training with True-Time-Delay Array Architecture,” presented at the 2019 53rd Asilomar Conference on Signals, Systems, and Computers, Pacific Grove, CA, November 3-6, 2019.

O. F. Castaneda Fernandez, S. Jacobsson, G. Durisi, T. Goldstein, & C. Studer, “Finite-Alphabet Wiener Filter Precoding for mmWave Massive MU-MIMO Systems,” presented at the 2019 53rd Asilomar Conference on Signals, Systems, and Computers, Pacific Grove, CA, November 3-6, 2019.

A. Farid, A. Simsek, A. Ahmed, M. Rodwell, “A Broadband Direct Conversion Transmitter/Receiver at D-band Using CMOS 22nm FDSOI,” presented at the  2019 IEEE Radio Frequency Integrated Circuits Symposium (RFIC), Boston, MA, USA, June 2-4, 2019.