Good thermoelectric materials should have low thermal conductivity, high electrical and Seebeck coefficient, which cannot be easily balanced in bulk materials. Exceptionally, the super-ionics β-Cu2Se can favorably contribute large ionic conductivity a liquid-like by Cu+ ions. In previous work, superionic mechanism was found to enhanced small randomly orientated lamellae with alternating ordered Se ion monolayer disordered Cu bilayers. Here, we further enhance increasing better aligning...

This paper proposes a new iterative receiver for single-carrier multiple-input-multiple-output (SC-MIMO) underwater acoustic (UWA) communications, which utilizes frequency-domain turbo equalization (FDTE) and channel estimation. Soft-decision symbols are not only fed back to the equalizer cancel intersymbol interference (ISI) cochannel (CCI), but also used as training signals in estimator update estimated state information (CSI) after each iteration. estimation scheme helps combat problem...

Satellite computing represents a recent computational paradigm in the development of low Earth orbit (LEO) satellites. It aims to augment capabilities LEO satellites beyond their current transparent relay functions by enabling real-time processing, thereby providing low-latency services end users. In constellations, significant deployment computationally capable is orchestrated offer enhanced resources. Challenges arise optimal allocation terminal most suitable satellite due overlapping...

We employed high‐energy ball‐milling technique to fabricate TiO/TiO 2 heterogeneous nanostructures. XRD proved the existence of structures. SEM and HRTEM investigation evidenced that mean particle size grain as‐prepared samples are 23 nm 13 nm, respectively. UV‐Vis spectra exhibited TiO has enhanced visible light absorption changed E g . UPS examination indicated electron work function (EWF) is higher than Photocatalytic degradation experiments revealed an appropriate content can enhance...

This paper presents the hardware implementation of a Direct-Sequence Spread Spectrum (DSSS) modem with networking capability for underwater acoustic sensor networks. The platform uses Texas Instrument Digital Signal Processor (DSP) physical layer transmission/receiving and microcontroller network control node ID detection. system 125 kHz single carrier Binary Phase Shift Keying (BPSK) code modulation DSSS payload data. For data detection, adaptive channel estimation is implemented to track...

In this paper, we propose a time-domain oversampled receiver for orthogonal frequency division multiplexing (OFDM) in underwater acoustic communication. Without changing the structure of transmitter, significant gains are acquired by time- domain oversampling at receiver. Using oversampling, energy transmitted symbols is concentrated on first N subcarriers, while additive Gaussian noises distributed all subcarriers. Because sparsity channels, most channel impulse responds few paths, and...

This paper proposes a low-complexity dual pseudorandom noise (PN) scheme for identity (ID) detection and coarse frame synchronization. The two PN sequences are identical separated by specified length of gap which serves as the ID different sensor nodes. receiver is implemented on microcontroller MSP430F5529 calculating correlation between segments received signal with separation gap. When matched ID, correlator outputs peak sets wakeup enable. time index used synchronization data frame. An...

In this paper, we study the design of frequency domain turbo equalization (FDTE) in single carrier (SC) multiple-input multiple-output (MIMO) systems, and prove equivalence two typical FDTE schemes under constant-modulus modulation. schemes, received signals soft decision symbols obtained at previous iteration are utilized to recover transmitted minimum mean squared error (MMSE) criterion. Frequency with feedback (FDE- FDDF), parallel interference cancellation (FDE-PIC) presented details....

In this paper, we study the design of frequency domain turbo equalization (FDTE) in single carrier (SC) multiple-input multiple-output (MIMO) systems, and prove equivalence two typical FDTE schemes under constant-modulus modulation. schemes, received signals soft decision symbols obtained at previous iteration are utilized to recover transmitted minimum mean squared error (MMSE) criterion. Frequency with feedback (FDE- FDDF), parallel interference cancellation (FDE-PIC) presented details....

This paper investigates two typical frequency-domain turbo equalization (FDTE) schemes, i.e., (FDE) with parallel interference cancelation (FDE-PIC) and FDE decision feedback (FDE-FDDF) in single-carrier (SC) multiple-input-multiple-output (MIMO) systems. These FDTE schemes are proven to be equivalent under the condition that we derived. We discover covariance matrix of low-complexity FDE-PIC scheme correlation FDE-FDDF satisfy a unique relationship for constant-modulus modulations, original...

In this paper, we propose a low-complexity single- carrier frequency-domain iterative receiver for triply-selective underwater acoustic (UWA) fading channels, which combines frequency domain decision feedback equalization (FD-DFE) with channel estimation. Due to long multipath turbo has use large block size achieve low computational complexity and high data efficiency, but UWA coherence time is often much shorter than length. We utilize pilots or soft symbols obtained at the previous...

In this paper, an iterative receiver with Turbo equalization and soft demapping is proposed for high data rate communication in multipath channels. Minimum mean square error (MMSE) adopted to avoid noise enhancement. With the assumption that distribution of estimated symbols Gaussian distribution, log likelihood ratios (LLR) encoded bits are obtained demapping. Using BCJR decoding algorithm, means variances transmitted calculated, then fed back equalizer as priori information following...

In this paper, a new equalization method without noise enhancement is proposed for dual PN padding TDS-OFDM systems. Using identical sequences as training sequences, payload and the subsequent sequence form joint block. The preceding treated cyclic prefix of block, which leads to low-complexity using single carrier frequency domain (SC-FDE) techniques. does not utilize overlap-add (OLA) operations reconstruct circular convolution, avoids caused by OLA operations. Furthermore, reconstruction...

SiGe, as a reliable and most efficient high-temperature thermoelectrics, has been utilized in special fields for many years, but there is no large-scale commercial application due to its high cost low efficiency. Therefore, it necessary improve the dimensionless figure of merit ZT Si-based system, free Ge which expensive rare earth, thereby becoming competitive efficiency application. Since pure silicon possesses rather ZT, example 0.01 at room temperature, we have developed doped...