1 Motivation and specification.............................................................................................. 2 2 Implementation of interpolation filters for audio DACs.................................................... 4 2.1 Interpolator filter partitioning..................................................................................... 4 2.2 Interpolator filter structures....

This brief presents a new topology of a multibit quadrature band-pass sigma-delta modulator which employs a simple dynamic element matching (DEM) technique in order to reduce the effects of path mismatch, namely aliasing in the signal band of the mirror images of the signal and of the quantization noise. The DEM scheme results in a reduction of the aliasing of the quantization noise mirror imag...

The deployment of large-scale antenna arrays for cellular base stations (BSs), called massive MIMO, has been a key enabler meeting the ever increasing capacity requirement 5G communication systems and beyond. Despite their promising performance, fully digital MIMO require large number hardware components including radio frequency chains, power amplifiers, digital-to-analog converters (DACs), so...

We present a novel non-linear precoding technique for the transmission of 16 quadrature amplitude modulation (QAM) symbols in a 1-bit massive multi-user (MU) multipleinput-single-output (MISO) downlink system. We deploy low resolution digital-to-analog converters (DACs) at the transmitter for the sake of decreasing the high energy consumption related to the massive MISO system. To mitigate the ...

Time-interleaved ∆Σ (TIDSM) DACs have the potential for a wideband operation. The performance of a twochannel interleaved ∆Σ DAC is very sensitive to the duty-cycle of the half-rate clock. This paper presents a closed-form expression for the SNDR loss of such DACs due to duty cycle error for modulators with a noise transfer function of (1 − z−1). Adding a low-order FIR filter after the modulato...

We propose a nonlinear phase-quantized constantenvelope precoding algorithm for the massive multi-user (MU) multiple-input multiple-output (MIMO) downlink. Specifically, we adapt the squared-infinity norm Douglas-Rachford splitting (SQUID) precoder to systems that use oversampling digital-toanalog converters (DACs) at the base station (BS) and orthogonal frequency-division multiplexing (OFDM) t...

Abstract The winds of hot, massive stars are variable from processes happening on both large and small spatial scales. A particular case such wind variability is ‘discrete-absorption components’ (DACs) that manifest themselves as outward moving density features in UV resonance line spectra. Such DACs believed to be caused by large-scale spiral-shaped structures the stellar wind. We consider nov...