Multi-group frequency hopping OFDMA based on statistical multiplexing

In this paper, the multi-group frequency hopping OFDMA (MG-FH OFDMA) based on the statistical multiplexing is proposed for the downlink cellular system. Compared with the existed random frequency hopping OFDMA (RFH-OFDMA) system utilizing the statistical multiplexing, the proposed MG-FH OFDMA invokes the deterministic hopping pattern to reduce the number of subcarrier collisions. By dividing all users into different groups, the subcarriers are utilized sufficiently. Latin Square hopping pattern and user index updating scheme are applied to randomize the subcarrier collisions among users. The user capacity, defined as the maximum number of users served with a basic data-rate in a cell, is calculated with the consideration of intra-cell capacity and the other cell interference (OCI). Results show that the proposed MG-FH OFDMA achieves higher user capacity than that of the RFH-OFDMA

Approximate minimum BER power allocation for MIMO-THP system

This paper proposes a transmit power allocation (TPA) scheme based on multiple-input multiple-output (MIMO) Tomlinson-Harashima precoding (THP) structure, where a TPA matrix is introduced to the conventional MIMO-THP. We analyze the influence of the introduced TPA matrix on the performance of MIMO-THP. The proposed TPA scheme invokes the minimum average uncoded bit-error rate (BER) criterion subjected to a sum-power constraint. During the derivation, we consider the effects of precoding loss factor on the TPA scheme and obtain a closed-form expression of the TPA. Compared to existing TPA methods for MIMO-THP systems, the proposed scheme reduces processing complexity and improves the BER performance

Active inductor shunt peaking in high-speed VCSEL driver design

An all transistor active inductor shunt peaking structure has been used in a prototype of 8-Gbps high-speed VCSEL driver which is designed for the optical link in ATLAS liquid Argon calorimeter upgrade. The VCSEL driver is fabricated in a commercial 0.25-um Silicon-on-Sapphire (SoS) CMOS process for radiation tolerant purpose. The all transistor active inductor shunt peaking is used to overcome the bandwidth limitation from the CMOS process. The peaking structure has the same peaking effect as the passive one, but takes a small area, does not need linear resistors and can overcome the process variation by adjust the peaking strength via an external control. The design has been tapped out, and the prototype has been proofed by the preliminary electrical test results and bit error ratio test results. The driver achieves 8-Gbps data rate as simulated with the peaking. We present the all transistor active inductor shunt peaking structure, simulation and test results in this paper.Comment: 4 pages, 6 figures and 1 table, Submitted to 'Chinese Physics C

Color watermarking algorithm combining the quantum discrete cosine transform with the sinusoidal–tent map

To overcome the drawbacks of the existing sinusoidal map and tent map, this paper proposes the design of a sinusoidal–tent (ST) map. The test results indicate that the new chaotic system exhibits more significant advantages in chaos control. Compared with the sinusoidal map and tent map, the proposed sinusoidal–tent map performs better in terms of bifurcation diagram and Lyapunov exponents. The trajectories of the sinusoidal–tent map can occupy all the phase planes over (0,4), while those of the two classic maps only occupy a small phase space, and the Lyapunov exponents of the ST map are all positive within the range of control parameters, higher than those of seed maps. Simultaneously, a novel quantum scrambling operation is devised based on the sinusoidal–tent map to avoid the periodicity of the quantum Arnold scrambling method. Initially, two chaotic sequences are generated to scramble the pixel positions of the watermark image, further enhancing the security of the watermarking algorithm. Subsequently, the host image is processed by the quantum discrete cosine transform, and finally, the scrambled watermark image is inserted into the medium-frequency band of the transformed host image, ensuring the invisibility of the watermarking. According to the simulation results, the quantum watermarking algorithm has excellent invisibility and robustness

Transcriptome sequencing and phylogenomic resolution within Spalacidae (Rodentia)

BACKGROUND: Subterranean mammals have been of great interest for evolutionary biologists because of their highly specialized traits for the life underground. Owing to the convergence of morphological traits and the incongruence of molecular evidence, the phylogenetic relationships among three subfamilies Myospalacinae (zokors), Spalacinae (blind mole rats) and Rhizomyinae (bamboo rats) within the family Spalacidae remain unresolved. Here, we performed de novo transcriptome sequencing of four RNA-seq libraries prepared from brain and liver tissues of a plateau zokor (Eospalax baileyi) and a hoary bamboo rat (Rhizomys pruinosus), and analyzed the transcriptome sequences alongside a published transcriptome of the Middle East blind mole rat (Spalax galili). We characterize the transcriptome assemblies of the two spalacids, and recover the phylogeny of the three subfamilies using a phylogenomic approach. RESULTS: Approximately 50.3 million clean reads from the zokor and 140.8 million clean reads from the bamboo ratwere generated by Illumina paired-end RNA-seq technology. All clean reads were assembled into 138,872 (the zokor) and 157,167 (the bamboo rat) unigenes, which were annotated by the public databases: the Swiss-prot, Trembl, NCBI non-redundant protein (NR), NCBI nucleotide sequence (NT), Gene Ontology (GO), Cluster of Orthologous Groups (COG), and Kyoto Encyclopedia of Genes and Genomes (KEGG). A total of 5,116 nuclear orthologous genes were identified in the three spalacids and mouse, which was used as an outgroup. Phylogenetic analysis revealed a sister group relationship between the zokor and the bamboo rat, which is supported by the majority of gene trees inferred from individual orthologous genes, suggesting subfamily Myospalacinae is more closely related to subfamily Rhizomyinae. The same topology was recovered from concatenated sequences of 5,116 nuclear genes, fourfold degenerate sites of the 5,116 nuclear genes and concatenated sequences of 13 protein coding mitochondrial genes. CONCLUSIONS: This is the first report of transcriptome sequencing in zokors and bamboo rats, representing a valuable resource for future studies of comparative genomics in subterranean mammals. Phylogenomic analysis provides a conclusive resolution of interrelationships of the three subfamilies within the family Spalacidae, and highlights the power of phylogenomic approach to dissect the evolutionary history of rapid radiations in the tree of life

Development of A 16:1 serializer for data transmission at 5 Gbps

Radiation tolerant, high speed and low power serializer ASIC is critical for optical link systems in particle physics experiments. Based on a commercial 0.25 μm silicon-onsapphire CMOS technology, we design a 16:1 serializer with 5 Gbps serial data rate. This ASIC has been submitted for fabrication. The post-layout simulation indicates the deterministic jitter is 54 ps (pk-pk) and random jitter is 3 ps (rms). The power consumption of the serializer is 500 mW. The design details and post layout simulation results are presented in this paper

High-Speed Serial Optical Link Test Bench Using FPGA with Embedded Transceivers

We develop a custom Bit Error Rate test bench based on Altera’s Stratix II GX transceiver signal integrity development kit, demonstrate it on point-to-point serial optical link with data rate up to 5 Gbps, and compare it with commercial stand alone tester. The 8B/10B protocol is implemented and its effects studied. A variable optical attenuator is inserted in the fibre loop to induce transmission degradation and to measure receiver sensitivity. We report comparable receiver sensitivity results using the FPGA based tester and commercial tester. The results of the FPGA also shows that there are more one-tozero bit flips than zero-to-one bit flips at lower error rate. In 8B/10B coded transmission, there are more word errors than bit flips, and the total error rate is less than two times that of non-coded transmission. Total error rate measured complies with simulation results, according to the protocol setup

The Design of a High Speed Low Power Phase Locked Loop

The upgrade of the ATLAS Liquid Argon Calorimeter readout system calls for the development of radiation tolerant, high speed and low power serializer ASIC. We have designed a phase locked loop using a commercial 0.25-μm Silicon-on- Sapphire (SoS) CMOS technology. Post-layout simulation indicates that tuning range is 3.79 – 5.01 GHz and power consumption is 104 mW. The PLL has been submitted for fabrication. The design and simulation results are presented

The value of total tumor diameter in unilateral multifocal papillary thyroid carcinoma: a propensity score matching analysis

BackgroundTumor multifocality is frequently observed in papillary thyroid carcinoma (PTC). However, the maximum tumor diameter (MTD), currently utilized in various staging schemes, might not accurately indicate the level of aggressiveness exhibited by multifocal tumors. We aimed to investigate the relationship between total tumor diameter (TTD) and clinicopathological features of papillary thyroid carcinoma.MethodsRetrospective data analysis was done on 1936 individuals who underwent complete thyroidectomy for PTC. Patients were classified into subgroups according to unilateral multifocality, central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM). The relationships of clinicopathological features among these groups were analyzed.ResultsUnilateral multifocality was observed in 117 patients. The clinicopathological features of the unilateral multifocal PTC were similar to the unifocal PTC with approximate TTD. The unilateral multifocality played no independent role in CLNM and LLNM. Moreover, the efficiency of TTD in predicting CLNM and LLNM was significantly higher than that of MTD.ConclusionIn the case of unilateral multifocal PTC, TTD is a more accurate indicator of the biological characteristics of the tumor than MTD