Quantum Multiuser Communication Systems with
Adaptive Feedback Measurement and
Chip-Interleaved Iter-PIC Receiver
Lingda Wang, Xiaolin Zhou and Pengfei Tian
The Key Laboratory for Information Science of Electromagnetic Waves,
School of Information Science and Technology,
Fudan University, Shanghai, 200433, China
Email: zhouxiaolin@fudan.edu.cn
Abstract—One of the most crucial challenges in large-scale
quantum communication systems is how to simultaneously trans-
mit quantum information among multiple users via a common
channel. In this paper, a novel non-orthogonal iterative quantum
multiuser communication system is proposed. Based on the
beam splitter network (BSN), we combine the independent
quantum-state signals of different users into a single transmission
channel. Furthermore, using photon-number-resolving detectors
(PNRDs) based quantum adaptive feedback positive operator
valued measurement, a chip-interleaved quantum iterative par-
allel interference cancellation (Iter-PIC) multiuser detection is
developed. From the simulation results, the proposed quantum
multiuser communication system can easily achieve 10
-7
bit
error rate (BER) performance at 42 photons per bit for 6 users
transmitting simultaneously. Also, from the extrinsic information
transfer trajectories (EXIT) analysis results, this quantum chip-
interleaved Iter-PIC system is verified to have robust and fast
convergence property in tough conditions, e.g. extra low receiving
signal energy and quantum mode mismatch. Moreover, we show
that the throughput of proposed quantum Iter-PIC system is
66.7% higher than that of the existing quantum wavelength
division multiple access (q-WDMA) communication systems.
I. INTRODUCTION
Quantum information transmission is becoming one of
the most promising topics in the field of communications.
Researches on quantum receivers and quantum communication
protocols have made substantial progress. Quantum receivers
such as Kennedy’s receiver [1] and Dolinar’s receiver [2]
which are physically realizable, are capable of exceeding the
bit error rate (BER) performance limit of classical receivers,
and approaching the Helstrom Limit (HL) [3] of quantum
receivers. Quantum communication protocols such as quantum
key distribution (QKD) and dense coding give new ways for
the data transmission.
As the number of users grows, the problems of multiple
channel access and quantum multiuser detection (MUD) will
certainly intensify, since many different users’ information
has to be transmitted over the same communication channel
at the same time. Yet, there is a paucity of quantum-state
multiuser communication studies in the literature. Although
lots of wavelength and code division multiple access based
multiuser systems have been studied in quantum communi-
Adaptive
Feedback
Measurements
Beam
Splitter
Network
User 1
User K
Transmitter
Optical Transmit
Device
Optical Transmit
Device
Fig. 1. The schematic of the q-Iter-PIC communication system.
cations [4]–[6], problems continue to present. The quantum
code division multiple access (q-CDMA) method of [4], [5]
sends information with the aid of chaotic encoding and chaotic
synchronization among transmitters and receivers. However,
since the chaotic synchronization is environmentally sensitive,
the q-CDMA is not readily realized. In a quantum wavelength
division multiple access (q-WDMA) scheme [6], having low
throughput is unavoidable. We notice that a non-orthogonal
quantum parallel interference cancellation (PIC) multiuser
communication system can be realized to solve problems and
insufficiencies in current quantum multiuser communication
studies.
In this paper, based on a beam splitter network (BSN), a new
non-orthogonal quantum iterative PIC (q-Iter-PIC) communi-
cation system is proposed. The contributions of this paper are:
(1) the quantum-state signals of multiple users are encoded and
transmitted simultaneously via a common quantum channel
with the aid of BSN. (2) with a photon-number-resolving
detectors (PNRDs) based quantum adaptive feedback posi-
tive operator valued measurement, a chip-interleaved Iter-PIC
communication system is developed, which exhibits low BER
performance, rapid iterative convergence and high throughput
performance.
In Section II, the system model of our q-Iter-PIC com-
munications is proposed. Section III analyzes the extrinsic
information transfer trajectories (EXIT) chart analysis, BER
performance evaluation and throughput comparison. Finally,
in Section IV, our conclusions are offered.
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