Quantum Annealing for Wireless

Analog quantum annealing platforms solve specific optimization problems

Our most mature line of work in quantum compute-enabled wireless networks examines ways of reducing a diverse set of NextG wireless baseband processing tasks to the form a quantum annealer optimizer device can accept, and benchmarking the resulting designs versus the status quo in conventional CMOS silicon.

Relevant Publications

We present the Hybrid Polar Decoder (HyPD), a hybrid of classical CMOS and quantum annealing (QA) computational structures for decoding Polar error correction codes, which are becoming widespread in today's 5G and tomorrow's 6G networks. Our results show that HyPD outperforms successive cancellation list decoders of list size eight by half an order of bit error rate magnitude at 1 dB SNR. Further studies address QA compute time at various coding rates, and with increased qubit numbers.

With unprecedented increases in traffic load in today's wireless networks, design challenges shift from the wireless network itself to the computational support behind the wireless network. In this vein, there is new interest in quantum-compute approaches because of their potential to substantially speed up processing, and so improve network throughput. However, quantum hardware that actually exists today is much more susceptible to computational errors than silicon-based hardware, due to the physical phenomena of decoherence and noise. This paper explores the boundary between the two types of computation–-classical-quantum hybrid processing for optimization problems in wireless systems–-envisioning how wireless can simultaneously leverage the benefit of both approaches. We explore the feasibility of a hybrid system with a real hardware prototype using one of the most advanced experimentally available techniques today, reverse quantum annealing. Preliminary results on a low-latency, large MIMO system envisioned in the 5G New Radio roadmap are encouraging, showing approximately 2–10\times× better performance in terms of processing time than prior published results.

User demand for increasing amounts of wireless capacity continues to outpace supply, and so to meet this demand, significant progress has been made in new MIMO wireless physical layer techniques.  Higher-performance systems now remain impractical largely only because their algorithms are extremely computationally demanding.  For optimal performance, an amount of computation that increases at an exponential rate both with the number of users and with the data rate of each user is often required. The base station s computational capacity is thus becoming one of the key limiting factors on wireless capacity.  QuAMax is the first large MIMO cloud-based radio access network design to address this issue by leveraging quantum annealing on the problem. We have implemented QuAMax on the 2,031 qubit D-Wave 2000Q quantum annealer, the state-of-the-art in the field.  Our experimental results evaluate that implementation on real and synthetic MIMO channel traces, showing that 30 US of compute time on the 2000Q can enable 48 user, 48 AP antenna BPSK communication at 20 dB SNR with a bit error rate of 10^(-6) and a 1,500 byte frame error rate of 10^(4).