Multi-Panel Extra-Large Scale MIMO Based Joint Activity Detection and Channel Estimation for Near-Field Massive IoT Access

The extra-large scale multiple-input multiple-output(XL-MIMO)for the beyond fifth/sixth generation mobile communications is a promising technology to provide Tbps data transmission and stable access service.However,the extremely large antenna array aperture arouses the channel near-field effect,resulting in the deteriorated data rate and other challenges in the practice communication systems.Meanwhile,multi-panel MIMO technology has attracted extensive attention due to its flexible configuration,low hardware cost,and wider coverage.By combining the XL-MIMO and multi-panel array structure,we construct multi-panel XL-MIMO and apply it to massive Internet of Things(IoT)access.First,we model the multi-panel XL-MIMO-based near-field channels for massive IoT access scenarios,where the electromagnetic waves corresponding to different panels have different angles of arrival/departure(AoAs/AoDs).Then,by exploiting the sparsity of the near-field massive IoT access channels,we formulate a compressed sensing based joint active user detection(AUD)and channel estimation(CE)problem which is solved by AMP-EM-MMV algorithm.The simulation results exhibit the superiority of the AMP-EM-MMV based joint AUD and CE scheme over the baseline algorithms.

MmWave extra-large-scale MIMO based active user detection and channel estimation for high-speed railway communications

The current High-Speed Railway(HSR)communications increasingly fail to satisfy the massive access services of numerous user equipment brought by the increasing number of people traveling by HSRs.To this end,this paper investigates millimeter-Wave(mmWave)extra-large scale(XL)-MIMO-based massive Internet-of-Things(loT)access in near-field HSR communications,and proposes a block simultaneous orthogonal matching pursuit(B-SOMP)-based Active User Detection(AUD)and Channel Estimation(CE)scheme by exploiting the spatial block sparsity of the XLMIMO-based massive access channels.Specifically,we first model the uplink mmWave XL-MIMO channels,which exhibit the near-field propagation characteristics of electromagnetic signals and the spatial non-stationarity of mmWave XL-MIMO arrays.By exploiting the spatial block sparsity and common frequency-domain sparsity pattern of massive access channels,the joint AUD and CE problem can be then formulated as a Multiple Measurement Vectors Compressive Sensing(MIMV-CS)problem.Based on the designed sensing matrix,a B-SOMP algorithm is proposed to achieve joint AUD and CE.Finally,simulation results show that the proposed solution can obtain a better AUD and CE performance than the conventional CS-based scheme for massive IoT access in near-field HSR communications.

QTL Mapping for Grain Size Traits Based on Extra-Large Grain Rice Line TD70

Grain size traits, including grain length, grain width and grain thickness, are controlled by quantitative trait loci （QTLs）. Many QTLs relating to rice grain size traits had been reported, but their control mechanisms have not yet been elucidated. A recombinant inbred line （RIL） population of 240 lines, deriving from a cross between TD70, an extra-large grain size japonica line with 80 g of 1000-grain weight, and Kasalath, a small grain size indica variety, were constructed and used to map grain size QTLs to a linkage map by using 141 SSR markers in 2010 and 2011. Five QTLs for grain length, six for grain width and seven for grain thickness were detected distributing over chromosomes 2, 3, 5, 7, 9 and 12. Seven QTLs, namely qGL3.1, qGW2, qGW2.2, qGW5.1, qGW5.2, qGT2.3 and qGT3.1, were detected in either of the two years and explained for 56.19%, 4.42%, 29.41%, 10.37%, 7.61%, 21.19% and 17.06% of the observed phenotypic variances on average, respectively. The marker interval RM1347-RM5699 on chromosome 2 was found common for grain length, grain width and grain thickness; qGL3.1 and qGT3.1 were mapped to the same interval RM6080-RM6832 on chromosome 3. All 18 QTL alleles were derived from the large grain parent TD70. Most of the QTLs mapped in the present study were found the same as the genes previously cloned （GW2, GS3 or qGL3, GW5 and GS5）, and several were the same as the QTLs （GS7 and qGL-7） previously mapped. Three QTLs, qGL2.2 on chromosome 2, qGW9 and qGT9 on chromosome 9, were first detected. These results laid a foundation for further fine mapping or cloning of these QTLs.

Extra-large Undersea Shield Tunnel in Composite Ground:Maliuzhou Traffic Tunnel in Zhuhai

1Project objective Extra-large shield tunnels have become the best choice for urban transportation tunnels due to the advantage of taking the best use of underground space.Hengqin Island in Zhuhai is a demonstration area to explore a new cooperation mode among Guangzhou,Hong Kong and Macao,which is also an important pivot of the 21st Century Maritime Silk Road.Thus,it takes an important role in serving Hong Kong and Macao and driving the economic development of the Pearl River Delta.However,as typhoons are frequent in Zhuhai,Hengqin Island will be isolated to the mainland when bridges are obstructed in typhoon seasons.Therefore,the bridges cannot satisfy the traffic demand to the island.The inconvenient transportation has a neglect influence on production and live of people on the island,which also affects the long term development of Hengqin Island.Apart from the two existed bridges,Maliuzhou Traffic Tunnel in Zhuhai is the third major link of Hengqin Island to the mainland,which will put an end to the"losing connectionM problem due to obstructing the bridges in typhoon seasons.This linkage is able to promote Zhuhai tourism exploitation and the long term development of the city,and also increase the security of peopled lives.Meanwhile,the construction of the Maliuzhou Traffic Tunnel has conquered the challenges in designing and building of the extra-large shield tunnel in composite ground and undersea circumstances.The designing methods and constructing approaches used in this project will provide theoretical supports and technical guarantees to similar projects.

Failure process and monitoring data of an extra-large landslide at the Nanfen Open-pit Iron Mine

An extra-large landslide occurred on June 19,2021,on the footwall slope of the Nanfen Open-pit Iron Mine in Liaoning Province,China,with a volume of approximately 1.2×107 m3.To elucidate the causative factors,development process,and destructive mechanisms of this catastrophic landslide,comprehensive field tests,investigations,and laboratory experiments were conducted.Initially,the heavily weathered rock mass of the slope was intersected by faults and joint fissures,facilitating rainwater infiltration.Moreover,the landslide contained a substantial clay mineral with highly developed micro-cracks and micro-pores,exhibiting strong water-absorption properties.As moisture content increased,the rock mass underwent softening,resulting in reduced strength.Ultimately,continuous heavy rainfall infiltration amplified the slope's weight,diminishing the weak structural plane's strength,leading to fracture propagation,slip plane penetration,and extensive tensile-shear and uplift failure of the slope.The study highlights poor geological conditions as the decisive factor for this landslide,with continuous heavy rainfall as the triggering factor.Presently,adverse environmental factors persistently affect the landslide,and deformation and failure continue to escalate.Hence,it is imperative to urgently implement integrated measures encompassing slope reinforcement,monitoring,and early-warning to real-time monitor the landslide's deformation and deep mechanical evolution trends.

Performance analysis and low complexity receiver design for extra-large scale MIMO systems with residual hardware impairments

The research purpose of this paper is focused on investigating the performance of extra-large scale massive multiple-input multiple-output(XL-MIMO)systems with residual hardware impairments.The closed-form expression of the achievable rate under the match filter(MF)receiving strategy was derived and the influence of spatial non-stationarity and residual hardware impairments on the system performance was investigated.In order to maximize the signal-to-interference-plus-noise ratio(SINR)of the systems in the presence of hardware impairments,a hardware impairments-aware minimum mean squared error(HIA-MMSE)receiver was proposed.Furthermore,the stair Neumann series approximation was used to reduce the computational complexity of the HIA-MMSE receiver,which can avoid matrix inversion.Simulation results demonstrate the tightness of the derived analytical expressions and the effectiveness of the low complexity HIA-MMSE(LC-HIA-MMSE)receiver.

Synthesis of Extra-large Pore of Zeolite Mineral

In the late 1970s, the discovery of the alumindnophosphate molecular sieveminerals which have been called a new generation led to framework composition oxideoutside of the aluminium-silicon system. The largest secondary building unit (SBU)of 18 T-atom rings has been maintained more than 180 years[2]. Only just in 1988,the molecular sieve with eighteen membered-ringr was reported by Davis and calledVIP-5 after the Virginia Polytechnic Institute. But a dissent has been expressed byDuncan for this. It was considered that VPI-5 does not represent a