A QUANTUM MULTIPLE ACCESS COMMUNICATIONS SCHEME USING ORBITAL ANGULAR MOMENTUM

We propose a quantum multiple access communications scheme using Orbital Angular Momentum (OAM) sector states in the paper. In the scheme, each user has an individual modified Poincare Bloch sphere and encodes his information with his own corresponding sector OAM states. A prepared entangled photon pairs are separated at transmitter and receiver. At the transmitter, each user encodes his information with the sector OAM states on the photons and the superposition of the different sector OAM states is carried by the photons. Then the photons are transmitted through quantum noiseless channel to the receiver. At the receiver, each user could retrieve his information by coincidently measuring the transmitted photons with the receiver side photons which are modulated by a special prepared measurement basis. The theoretical analysis and the numerical simulations show that each user could get his information from the superposition state without error. It seems that this scheme provides a novel method for quantum multiple users communications.

ZTE Communications Special Issue on Multiple Access Techniques for 5G

5G mobile cellular networks are required to provide the significant increase in network throughput, cell-edge data rate, massive connectivity, superior spectrum efficiency, high energy efficiency and low latency, compared with the currently deploying long-term evolution （LTE） and LTE-advanced networks. To meet these challenges of 5G networks, innovative technologies on radio air-interface and radio access network （RAN） are important in PHY design. Recently,

ZTE Communications Special Issue on Multiple Access Techniques for 5G

5G mobile cellular networks are required to provide the significant increase in network throughput,cell-edge data rate,massive connectivity,superior spectrum efficiency,currently deploying long-term evolution(LTE)and LTE-advanced networks.To meet these challenges of 5G networks,

Visible light communication based on space-division multiple access optical beamforming

We propose and demonstrate a visible light communication （VLC） scheme based on space-division multiple access （SDMA） optical beamforming to accommodate multiple user devices in the VLC based on optical beamforming. SDMA optical bealnforming is a technique which separates light-emitting diode light spa- tially and focuses each part on different target devices simultaneously. We show the experimental results of the VLC signal amplitudes, the optical power densities, and the bit-error rate performance as a function of transmission distance before and after the SDMA optical beamforming. The results show that the VLC signal amplitudes and optical power densities are improved by 8-2 and 3.8- 5 dB, respectively, with the help of SDMA optical beamforming.

A LARGE CLASS OF BINARY ZCZ SEQUENCE FAMILIES CONSTRUCTED BY PERIOD DOUBLING

In an Approximately Synchronized Code Division Multiple Access (AS-CDMA) commu-nication system,a family with large number of Zero Correlation Zone (ZCZ) sequences is desired,which can satisfy the rapid increase of users. This paper presents a method to generate a (2L ,2M ,Zc' z )-ZCZsequence family from an original (L ,M ,Z cz)-ZCZsequence family,where Z c' z =Zcz if Z czis even and Z c' z = Zcz 1if Z czis odd. This method can also recursively act on a ZCZ sequence family to construct a series of ZCZ sequence families with large sequence number and zero correlation zone length identical to or one less than that of original ZCZ sequences.