Baseband Design for 5G UDN Base Stations:Methods and Implementation

Baseband design and implementation for micro/pico base stations （mBS） in 5G ultra-dense network （UDN） is studied. Low cost is an essential requirement for mBS baseband in UDN. Digital baseband cost of ASIC/ASIP （Application Specific Integrated Circuit / Instruction-set processor） is of the most uncertainty in roBS system. However. the actual costs and hardware feasibility of the baseband are yet unknown to network deployers and researchers. In this paper, we studied the baseband hardware system design and implementation for low-cost roBS. We analyzed popular baseband algorithms and architectures for both full-digital and hybrid beamforming （BF） for UDN. We then proposed feasible chip-level solutions for the baseband with up to 128-antenna BS system, and estimated their implementation cost. Results show that among lull-digital BF algorithms, zero-forcing is a choice of high performance and low cost; for hybrid BF, 4×32 architecture （32 RF chains） provides good reduction in baseband cost with acceptable performance loss, thus it can be a preferable solution under low cost consider- ation. The proposed system planning method can also be used for the design of other related systems.

Jitter Enhanced Full Digital RF Transmitter and PWM RFPA for 5G Broadband Communications

RFPA(radio frequency power amplifier)based on PWM(pulse width modulation)can be perfect linear without using complicated DPD(digital pre-distortion)hardware.However,PWM RFPA need ultra-high PWM time resolution(less than 10 ps)for wide-band 5G,which is limited by CMOS technologies(can reach 40 ps).It limits the complexity of modulation so that PWM RFPA cannot be really commercialized so far in wideband radio/mobile technologies.This paper presents our contribution by introducing jitter into PWM.For the first time,we demonstrate that jitter can improve the PWM time resolution equivalently reaching less than 2.6 ps.Hence PWM RFPA can be used in 5G supporting 256QAM OFDM modulation based on currently available digital CMOS technologies.We demonstrate that jitter can refine the inherent resolution of PWM hardware circuit modulation.The jitter makes the MCS(modulation and coding scheme)of the bandwidth OFDM system improved from 16QAM to 256QAM in the band n28 of 3GPP 38.101.We also verified that 5G 256QAM OFDM modulation is achievable in the 3GPP band n20,Softbank band28 and NTT Docomo band28.The RMS EVM(root mean square error vector magnitude)of 256QAM OFDM modulation is about-44 dB.

Ecological and Environmental Protection Requirements in China s Regional Coordinated Development Strategy in the New Era

Starting from the historical evolution of China s regional coordinated development policy and practice,three stages of"enlightenment stage","development stage"and"maturity stage",as well as the connotation,characteristics and content of implementing regional coordinated development strategy were analyzed.On this basis,from different aspects of industrial distribution,pollutant characteristics and regional environmental protection policy,the existing ecological and environmental protection problems in China s regional coordinated development in the new era were analyzed,and some suggestions for the next step were put forward.It is necessary to follow the"four ones"concept from the overall point of view,implement"three lines and one list"from the perspective of the width of the access red line,strengthen"joint prevention and control"from the perspective of the depth of regional regulation,deepen the"planning environmental impact assessment"from the perspective of the breadth of industrial distribution,and promote the"green-way model"from the perspective of ecological low carbon.

Energy Estimation and Optimization Platform for 4G and the Future Base Station System Early-Stage Design

There are already several power models to estimate the power consumption of base stations at system level. However, there is so far no model that can predict power consumption of the future base station designs based on algorithms and hardware selections with insufficient physical information. We present such an energy model for typical base stations. This model can help designers in estimating, evaluating and optimizing energy/power consumption of candidate designs in early design stages. The proposed model is verified by an LTE extreme scenario. The estimated results show that digital front-end, channel equalization and channel decoding are three major power greedy modules(consuming 39.4%, 16.3%, 13.4%) in a digital baseband subsystem. The power estimation error of the proposed power amplifier(PA) power model is 3.5%(macro cell). The major contribution of this paper is that the proposed models can rapidly estimate energy/power consumption of 4G and the future base stations(such as 5G) in early design stages with well acceptable precision, even without sufficient implementation information.

General Galois Processor for Transmitters in 5G/6G Base Stations

This paper proposes a flexible eight-mode high parallel Galois SIMD ASIP(Application Specific Instruction Set Processor).It supports parallel executions of Gold,Scrambling,CRC,CC,Turbo,RM,PSS,SSS encoding LFSR(linear feedback shift registers)algorithms with high performance and flexibility.It can perform also general bit processing and m-sequence.Our design is based on proposed table conversion and a datapath for unified eight-mode encoding.Based on 28 nm digital CMOS technology,the total area is 0.177 mm2 and the clock frequency can be up to 1 GHz.The throughputs of Gold,Scrambling,CRC32,CRC24,CRC16,CRC8,CC,Turbo are 64 Gb/s,64 Gb/s,128 Gb/s,168 Gb/s,256 Gb/s,512 Gb/s,3×80 Gb/s,and 72 Gb/s,respectively.

Register Allocation Compilation Technique for ASIP in 5G Micro Base Stations

The currently available compilation techniques are for general computing and are not optimized for physical layer computing in 5G micro base stations.In such cases,the foreseeable data sizes and small code size are application specific opportunities for baseband algorithm optimizations.Therefore,the special attention can be paid,for example,the specific register allocation algorithm has not been studied so far.The compilation for kernel sub-routines of baseband in 5G micro base stations is our focusing point.For applications of known and fixed data size,we proposed a compilation scheme of parallel data accessing,while operands can be mainly allocated and stored in registers.Based on a small register group(48×32b),the target of our compilation scheme is the optimization of baseband algorithms based on 4×4 or smaller matrices,maximizing the utilization of register files,and eliminating the extra register data exchanging.Meanwhile,when data is allocated into register files,we used VLIW(Very Long Instruction Word)machine to hide the time of data accessing and minimize the cost of data accessing,thus the total execution time is minimum.Experiments indicate that for algorithms with small data size,the cost of data accessing and extra addressing can be minimized.

N-Glycosylated type Ⅱ collagen peptides as therapeutic saccharide vaccines for rheumatoid arthritis

The interaction among type Ⅱ collagen(CⅡ),human DR4 major histocompatibility complex type Ⅱ molecule(MHC Ⅱ)and T-cell receptor(TCR)is associated with the development of rheumatoid arthritis(RA).The activation of T cells can be reduced through exposure to modified CⅡ(263-272)glycopeptide fragment via competitive inhibition with self-antigen.In this work,30 peptides based on the sequence of CⅡ(263-272)were prepared and evaluated for their binding to DR4 protein by surface plasmon resonance(SPR)assay.The effect on the secretion of pro-inflammatory factors by the spleen cells in collagen induced rheumatoid arthritis(CIA)mouse was also investigated.Two N-glycosylated CⅡ peptides were identified to have strong binding to the human recombinant DR4 protein and weak proinflammatory effect.These glycopeptides could be developed as therapeutic saccharide vaccines for the treatment of rheumatoid arthritis(RA).

Methods of DNA introduction for the engineering of commensal microbes

The microbiome is an essential component of ecological systems and is comprised of a diverse array of microbes.Over the past decades,the accumulated observational evidence reveals a close correlation between the micro-biome and human health and disease.Many groups are now manipulating individual microbial strains,species and the community as a whole to gain a mechanistic understanding of the functions of the microbiome.Here,we discuss three major approaches for introducing DNA to engineer model bacteria and isolated undomesticated bacteria,including transformation,transduction,and conjugation.We provide an overview of these approaches and describe the advantages and limitations of each method.In addition,we highlight examples of human mi-crobiome engineering using these approaches.Finally,we provide perspectives for the future of microbiome engineering.