Final Report Summary - BEAM-ME-UP (From Radio-Frequency to Giga-BitOptical- and Quantum-Wireless)
o Given the vulnerable nature of quantum circuits, the tiniest of environmental interference perturbs their quantum state, which is hence collapsed back into the classic world and all benefits of parallel processing in the quantum domain evaporate. Beam-Me-Up conceived near-optimal quantum error corrections codes for correcting both the bit-flips and phase-flips inflicted by the quantum decoherence phenomenon. At the current state-of-the-art these codes are vital for extending the coherence interval of all quantum circuits and computers.
o An important discovery - Quantum Topological Error Correction Codes: The Classical-to-Quantum Isomorphism Perspective
We conceived and investigated the new family of classical topological error correction codes (TECCs), which have the bits of a codeword arranged in a lattice structure. We then presented the classical-to-quantum isomorphism to pave the way for constructing their quantum-domain dual pairs, namely the quantum topological error correction codes (QTECCs). Finally, we characterized the performance of QTECCs in the face of the quantum depolarizing channel in terms of both their quantum-bit error rate (QBER) and their fidelity. At the current state-of-the-art our powerful near-hashing-bound codes having long codewords cannot be readily implemented, but these short topological codes are more suitable for hardware having short coherence-time.
o The second line of research contributed to making the perfectly secure ubiquitous quantum Internet a reality, which requires numerous radically new components, such as quantum-repeaters and quantum-key-distribution (QKD) solutions, which also require quantum-memory. Chinese scientists established quantum entanglement distribution over a record-distance of 1200 km, hence QKD may be deemed to be the most mature quantum technology, which is closest to commercial reality. Beam-Me-Up contributed a suite of new
network-coded QKD solutions, as well as to the conception of large-scale repeater networks with the aid of quantum-network-coding and entanglement-swapping investigations.
o Beam-Me-Up also exploited the formidable computing power of quantum-search algorithms (QSAs) - conceived by the computer-science-oriented quantum community - for solving numerous large-scale search problems found in wireless communications. This future-proof research simulated a future quantum-computer by a classic parallel computer. For example, large-scale multi-user detection problems were solved at the base-station (BS), where all K users supported in the mobile-to-BS uplink were simultaneously detected by using as few as square-root K cost-function evaluations. This search problem becomes extremely challenging for a large number of users, especially, when the system relies on high-throughput multi-level modulation schemes, as required by today's systems. An even more grave challenge is, when the BSs are interlinked by optical fibre and after exchanging their received information make a joint decision about all the users' information in all cells.
o Further cutting-edge solutions were conceived for other large-scale search problems, such as joint data and channel estimation and for
transmit preprocessing in support of multi-user transmission, where the knowledge of the downlink channel is exploited for eliminating the
potential inter-user interference that would be encountered in the hostile dispersive downlink channel. As a benefit, the mobile user would receive clean, flawless signal and hence low-complexity single-user reception can be invoked.
o Beam-Me-Up also designed new QSAs for futuristic localization-aided wireless services. Additionally, these QSAs were used for solving large-scale routing problems, such as those involved in Aeronautical Ad Hoc Networks.
o An important discovery - Quantum Topological Error Correction Codes: The Classical-to-Quantum Isomorphism Perspective
We conceived and investigated the new family of classical topological error correction codes (TECCs), which have the bits of a codeword arranged in a lattice structure. We then presented the classical-to-quantum isomorphism to pave the way for constructing their quantum-domain dual pairs, namely the quantum topological error correction codes (QTECCs). Finally, we characterized the performance of QTECCs in the face of the quantum depolarizing channel in terms of both their quantum-bit error rate (QBER) and their fidelity. At the current state-of-the-art our powerful near-hashing-bound codes having long codewords cannot be readily implemented, but these short topological codes are more suitable for hardware having short coherence-time.
o The second line of research contributed to making the perfectly secure ubiquitous quantum Internet a reality, which requires numerous radically new components, such as quantum-repeaters and quantum-key-distribution (QKD) solutions, which also require quantum-memory. Chinese scientists established quantum entanglement distribution over a record-distance of 1200 km, hence QKD may be deemed to be the most mature quantum technology, which is closest to commercial reality. Beam-Me-Up contributed a suite of new
network-coded QKD solutions, as well as to the conception of large-scale repeater networks with the aid of quantum-network-coding and entanglement-swapping investigations.
o Beam-Me-Up also exploited the formidable computing power of quantum-search algorithms (QSAs) - conceived by the computer-science-oriented quantum community - for solving numerous large-scale search problems found in wireless communications. This future-proof research simulated a future quantum-computer by a classic parallel computer. For example, large-scale multi-user detection problems were solved at the base-station (BS), where all K users supported in the mobile-to-BS uplink were simultaneously detected by using as few as square-root K cost-function evaluations. This search problem becomes extremely challenging for a large number of users, especially, when the system relies on high-throughput multi-level modulation schemes, as required by today's systems. An even more grave challenge is, when the BSs are interlinked by optical fibre and after exchanging their received information make a joint decision about all the users' information in all cells.
o Further cutting-edge solutions were conceived for other large-scale search problems, such as joint data and channel estimation and for
transmit preprocessing in support of multi-user transmission, where the knowledge of the downlink channel is exploited for eliminating the
potential inter-user interference that would be encountered in the hostile dispersive downlink channel. As a benefit, the mobile user would receive clean, flawless signal and hence low-complexity single-user reception can be invoked.
o Beam-Me-Up also designed new QSAs for futuristic localization-aided wireless services. Additionally, these QSAs were used for solving large-scale routing problems, such as those involved in Aeronautical Ad Hoc Networks.