A Universal Receiver for Uplink NOMA Systems

Given its capability in efficient radio resource sharing, non-orthogonal multiple access (NOMA) has been identified as a promising technology in 5G to improve the system capacity, user connectivity, and scheduling latency. A dozen of uplink NOMA schemes have been proposed recently and this paper considers the design of a universal receiver suitable for all potential designs of NOMA schemes. Firstly, a general turbo-like iterative receiver structure is introduced, under which, a universal expectation propagation algorithm (EPA) detector with hybrid parallel interference cancellation (PIC) is proposed (EPA in short). Link-level simulations show that the proposed EPA receiver can achieve superior block error rate (BLER) performance with implementation friendly complexity and fast convergence, and is always better than the traditional codeword level MMSE-PIC receiver for various kinds of NOMA schemes.Comment: This paper has been accepted by IEEE/CIC International Conference on Communications in China (ICCC 2018). 5 pages, 4 figure

Chinese Experience with Global G3 Standard-Setting

China’s growth strategy as set out in the 11th 5-year plan in 2005 called for upgrading of product quality, the development of an innovation society, and reduced reliance on foreign intellectual property with high license fees. Consistent with this policy, China has been involved in recent years with the development of a Chinese standard in third generation (3G) mobile phone technology, both in negotiating the standard and seeing it through to commercialization. This is the first case of a developing country both originating and successfully negotiating a telecommunications standard and this experience raises issues for China’s future development strategy based on product and process upgrading in manufacturing. We argue that while precedent setting from an international negotiating point of view, the experience has thus far is unproven commercially. But the lessons learned will benefit future related efforts in follow-on technologies if similar Chinese efforts are made.This paper documents Chinese standard-setting efforts from proposal submission to ITU to the current large-scale trial network deployment in China and overseas trial networks deployment. We discuss the underlying objectives for this initiative, evaluate its effectiveness, and assess its broader implications for Chinese development policy.

Experimental Demonstration of 100 Gbps/λ C-Band Direct-Detection Downstream PON Using Non-Linear and CD Compensation with 29 dB+ OPL over 0 Km-100 Km

Passive Optical Networks (PON), able to operate at 50 Gbps per wavelength (λ), are under development and standardization, based on intensity-modulation (IM) and direct-detection (DD) systems. The next step in PON evolution will be driven by 5G/6G fronthauling capacity demands, and will require the development of 100 Gbps/λ (and beyond) systems, which poses big challenges if maintaining the DD-format. In this contribution, we analyze a 100 Gbps/λ PON architecture able to preserve the IM-DD approach at the Optical Network Unit (ONU), placing the complexity at the Optical Line Terminal (OLT), thanks to Digital Signal Processing (DSP). We experimentally demonstrate a 100 Gbps/λ transmission using this architecture in the downstream (DS) direction. Chromatic dispersion digital pre-compensation (CD-DPC) in combination with an IQ Mach-Zehnder Modulator (IQ-MZM) is used at the transmitter (TX). Keeping the ONU DSP as simple as possible, as compared with current DSP proposals for 50 Gbps/λ PON, is another main goal of this work. Adaptive equalization (AEQ) is used to correct for linear impairments, in addition to digital non-linear correction (NLC) at the receiver (RX). We compare two NLC approaches: a full Volterra Non-Linear Equalizer (VNLE) and a simpler NLC technique based on a square-root like function (SQRT). Operation over standard single-mode fiber (SMF) in C-band, achieving reaches from 0 km to 100 km and Optical Path Loss (OPL) values higher than 29 dB, are shown. The analyzed proposal is directly applicable to Terabit-capable wavelength division multiplexing (WDM)-PON, and can be extended to very high-speed Time Division Multiplexing (TDM)-PON and TWDM-PON, with some modifications discussed here

On the Road to 6G: Visions, Requirements, Key Technologies and Testbeds

Fifth generation (5G) mobile communication systems have entered the stage of commercial development, providing users with new services and improved user experiences as well as offering a host of novel opportunities to various industries. However, 5G still faces many challenges. To address these challenges, international industrial, academic, and standards organizations have commenced research on sixth generation (6G) wireless communication systems. A series of white papers and survey papers have been published, which aim to define 6G in terms of requirements, application scenarios, key technologies, etc. Although ITU-R has been working on the 6G vision and it is expected to reach a consensus on what 6G will be by mid-2023, the related global discussions are still wide open and the existing literature has identified numerous open issues. This paper first provides a comprehensive portrayal of the 6G vision, technical requirements, and application scenarios, covering the current common understanding of 6G. Then, a critical appraisal of the 6G network architecture and key technologies is presented. Furthermore, existing testbeds and advanced 6G verification platforms are detailed for the first time. In addition, future research directions and open challenges are identified for stimulating the on-going global debate. Finally, lessons learned to date concerning 6G networks are discussed