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Wideband

About: Wideband is a research topic. Over the lifetime, 29217 publications have been published within this topic receiving 330810 citations.


Papers
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Journal ArticleDOI
TL;DR: This paper considers the challenging problem of blind sub-Nyquist sampling of multiband signals, whose unknown frequency support occupies only a small portion of a wide spectrum, and proposes a system, named the modulated wideband converter, which first multiplies the analog signal by a bank of periodic waveforms.
Abstract: Conventional sub-Nyquist sampling methods for analog signals exploit prior information about the spectral support. In this paper, we consider the challenging problem of blind sub-Nyquist sampling of multiband signals, whose unknown frequency support occupies only a small portion of a wide spectrum. Our primary design goals are efficient hardware implementation and low computational load on the supporting digital processing. We propose a system, named the modulated wideband converter, which first multiplies the analog signal by a bank of periodic waveforms. The product is then low-pass filtered and sampled uniformly at a low rate, which is orders of magnitude smaller than Nyquist. Perfect recovery from the proposed samples is achieved under certain necessary and sufficient conditions. We also develop a digital architecture, which allows either reconstruction of the analog input, or processing of any band of interest at a low rate, that is, without interpolating to the high Nyquist rate. Numerical simulations demonstrate many engineering aspects: robustness to noise and mismodeling, potential hardware simplifications, real-time performance for signals with time-varying support and stability to quantization effects. We compare our system with two previous approaches: periodic nonuniform sampling, which is bandwidth limited by existing hardware devices, and the random demodulator, which is restricted to discrete multitone signals and has a high computational load. In the broader context of Nyquist sampling, our scheme has the potential to break through the bandwidth barrier of state-of-the-art analog conversion technologies such as interleaved converters.

1,186 citations

Journal ArticleDOI
TL;DR: A memory polynomial model for the predistorter is proposed and implemented using an indirect learning architecture and linearization performance is demonstrated on a three-carrier WCDMA signal.
Abstract: Power amplifiers (PAs) are inherently nonlinear devices and are used in virtually all communications systems. Digital baseband predistortion is a highly cost-effective way to linearize PAs, but most existing architectures assume that the PA has a memoryless nonlinearity. For wider bandwidth applications such as wideband code-division multiple access (WCDMA) or wideband orthogonal frequency-division multiplexing (W-OFDM), PA memory effects can no longer be ignored, and memoryless predistortion has limited effectiveness. In this paper, instead of focusing on a particular PA model and building a corresponding predistorter, we focus directly on the predistorter structure. In particular, we propose a memory polynomial model for the predistorter and implement it using an indirect learning architecture. Linearization performance is demonstrated on a three-carrier WCDMA signal.

1,160 citations

Journal ArticleDOI
TL;DR: In this paper, the WALTZ-16 decoupling scheme was used for carbon-l 3 linewidth modulation with a 40% improvement in bandwidth over the original Waltz-16.

1,090 citations

Journal ArticleDOI
TL;DR: This paper presents a novel single-patch wide-band microstrip antenna: the E-shaped patch antenna, where two parallel slots are incorporated into the patch of a micro Strip antenna to expand it bandwidth.
Abstract: This paper presents a novel single-patch wide-band microstrip antenna: the E-shaped patch antenna. Two parallel slots are incorporated into the patch of a microstrip antenna to expand it bandwidth. The wide-band mechanism is explored by investigating the behavior of the currents on the patch. The slot length, width, and position are optimized to achieve a wide bandwidth. The validity of the design concept is demonstrated by two examples with 21.2% and 32.3% bandwidths. Finally, a 30.3% E-shaped patch antenna, resonating at wireless communication frequencies of 1.9 and 2.4 GHz, is designed, fabricated and measured. The radiation pattern and directivity are also presented.

989 citations

Journal ArticleDOI
TL;DR: In this paper, memory effects in the power amplifier limit the performance of digital predistortion for wideband signals, and novel algorithms that take into account such effects are proposed to solve the problem.
Abstract: Memory effects in the power amplifier limit the performance of digital predistortion for wideband signals. Novel algorithms that take into account such effects are proposed. Measured results are presented for single and multicarrier UMTS signals to demonstrate the effectiveness of the new approach.

934 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
20231,215
20222,826
20211,598
20202,005
20192,423