Efficiency Enhancement of Sigma–Delta Modulator Based Transmitters Using Multi-Level Quantizers

Boulejfen, Noureddine; Elsayed, Fahmi; Helaoui, Mohamed; Devocht, L.; Ghannouchi, Fadhel M.

doi:10.1007/s11265-011-0634-6

Cited by 6 publications

(5 citation statements)

References 6 publications

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“…Yet, using multi-level DSM that has more than three levels does not improve the overall transmitter efficiency, [1]. On the other side, higher order DSM, higher than 2 nd order, has stability issues, [5].…”

Section: Ccece 2014 1569880817mentioning

confidence: 99%

“…The OSR is selected to be 120 while Increasing OSR betterments the SNDR, [1]. The 1 st order DSM is represented by a difference equation 5.…”

Section: First Order Envelope Delta Sigma Modulatormentioning

confidence: 99%

“…Delta sigma modulator (DSM) starts to be a candidate for linear and high efficiency mobile transmitter architecture, [1]- [4]. Basically, high varying PAPR signal is shaped to a bilevel signal by DSM, then a high efficiency non-linear switched mode power amplifier is held to boost the power of the RF signal prior to transmission, Fig.…”

Section: Introductionmentioning

confidence: 99%

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Performance enhancement of first order three-level envelope delta sigma modulator based transmitter

Elsayed

Ibrahimi

Helaoui

et al. 2014

2014 IEEE 27th Canadian Conference on Electrical and Computer Engineering (CCECE)

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This work is concerned with the analysis, based on MATLAB simulation, of 1 st and 2 nd order Multi-level envelope delta sigma modulators (EDSMs) that are used for high efficiency and linearity wireless mobile transmitter architectures with an Orthogonal Frequency Division Modulation (OFDM) signal and long term evolution (LTE) signal. The analysis is based on measuring the linearity and the efficiency of the threelevel EDSM. It was shown that, at different input signal power levels of the three-level EDSM, 1 st order three-level EDSM is able to achieve a performance that is close to the performance of the 2 nd order counterpart. While 1 st order DSM requires less circuitry, it is recommended to employ 1 st order three-level EDSM instead of using 2 nd order three-level EDSM. 1 st order three-level EDSM has a signal to noise distortion ratio (SNDR) and coding efficiency of 58 dB and 77%, respectively. While 2 nd order three-level EDSM showed SNDR of 61.5 dB and coding efficiency of 76.4%. Also, with a long term evolution (LTE) signal, the 1 st order EDSM has better performance, in terms of SNDR and CE, than that of the 2 nd order EDSM circuit.

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Section: Ccece 2014 1569880817mentioning

confidence: 99%

“…The OSR is selected to be 120 while Increasing OSR betterments the SNDR, [1]. The 1 st order DSM is represented by a difference equation 5.…”

Section: First Order Envelope Delta Sigma Modulatormentioning

confidence: 99%

See 1 more Smart Citation

Performance enhancement of first order three-level envelope delta sigma modulator based transmitter

Elsayed

Ibrahimi

Helaoui

et al. 2014

2014 IEEE 27th Canadian Conference on Electrical and Computer Engineering (CCECE)

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“…The increasing demand of the new telecommunication standards in terms of bandwidth, spectral efficiency and power efficiency has led to the development of novel transceiver architectures and a continuous improvement in their performance. In the case of broadband and multi-standard Software Defined Radio (SDR) transmitters, Delta-Sigma Modulator (DSM)-based transmitters have shown a good linearity [ 1 ] and a high efficiency [ 2 ]. Particularly for transmitters where the requirements of high power efficiency, wide coverage range and autonomy are stringent.…”

Section: Introductionmentioning

confidence: 99%

Three-Level De-Multiplexed Dual-Branch Complex Delta-Sigma Transmitter

Arfi

Elsayed

Aflaki

et al. 2018

Sensors

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In this paper, a dual-branch topology driven by a Delta-Sigma Modulator (DSM) with a complex quantizer, also known as the Complex Delta Sigma Modulator (CxDSM), with a 3-level quantized output signal is proposed. By de-multiplexing the 3-level Delta-Sigma-quantized signal into two bi-level streams, an efficiency enhancement over the operational frequency range is achieved. The de-multiplexed signals drive a dual-branch amplification block composed of two switch-mode back-to-back power amplifiers working at peak power. A signal processing technique known as quantization noise reduction with In-band Filtering (QNRIF) is applied to each of the de-multiplexed streams to boost the overall performances; particularly the Adjacent Channel Leakage Ratio (ACLR). After amplification, the two branches are combined using a non-isolated combiner, preserving the efficiency of the transmitter. A comprehensive study on the operation of this topology and signal characteristics used to drive the dual-branch Switch-Mode Power Amplifiers (SMPAs) was established. Moreover, this work proposes a highly efficient design of the amplification block based on a back-to-back power topology performing a dynamic load modulation exploiting the non-overlapping properties of the de-multiplexed Complex DSM signal. For experimental validation, the proposed de-multiplexed 3-level Delta-Sigma topology was implemented on the BEEcube™ platform followed by the back-to-back Class-E switch-mode power amplification block. The full transceiver is assessed using a 4th-Generation mobile communications standard LTE (Long Term Evolution) standard 1.4 MHz signal with a peak to average power ratio (PAPR) of 8 dB. The dual-branch topology exhibited a good linearity and a coding efficiency of the transmitter chain higher than 72% across the band of frequency from 1.8 GHz to 2.7 GHz.

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“…In time-encoded DMPA, data is typically embedded in the transition time between two digital logic levels so that a single SMPA can be used in the front end. Encoding in time, either through delta-sigma modulation (DSM) [11]- [15] or pulse width modulation (PWM) [16], [17], takes advantage of improved transition time in deep sub-micron complementary metal-oxide-semiconductor (CMOS) technology and can achieve high resolution in time and robustness against process variations compared to amplitude encoding [18], but results in reduced coding efficiency. Since the overall efficiency of the DMPA is a combination of the coding efficiency in the encoder and the efficiency of the PA stage, previous work in general has demonstrated relatively low overall efficiency resulting from relatively low coding efficiency of DSM [19], [20] or PWM encoders [21].…”

Section: Introductionmentioning

confidence: 99%

A Hybrid Amplitude/Time Encoding Scheme for Enhancing Coding Efficiency and Dynamic Range in Digitally Modulated Power Amplifiers

Xia

Garg

Boumaiza

2013

IEEE J. Emerg. Sel. Topics Circuits Syst.

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Digitally modulated power amplifiers (DMPA) are a promising architecture for practical and highly efficient softwaredefined radio transmitters. Signal encoding schemes for DMPAs have primarily focused either on amplitude or time domain encoding, neither of which can simultaneously provide high coding efficiency, high dynamic range and low design complexity. In this paper, we propose, analyze and evaluate a new hybrid amplitude/ time signal encoding scheme that significantly improves the coding efficiency and dynamic range of DMPAs without significantly increasing design complexity. The proposed hybrid amplitude/time encoding scheme combines both the amplitude domain and the time domain to optimally encode information. Evaluation results show that hybrid amplitude/time encoding yields a 35% increase in the average coding efficiency with respect to conventional time encoding, and is only 6.7% lower than peak efficiency when applied to a Wireless Local Area Network signal with a peak to average power ratio equal to 9.9 dB. A new DMPA architecture, based on the proposed hybrid encoding, is also proposed.Index Terms-Digital encoder, digitally modulated power amplifier, pulse-width modulation, software-defined ratio.

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Efficiency Enhancement of Sigma–Delta Modulator Based Transmitters Using Multi-Level Quantizers

Cited by 6 publications

References 6 publications

Performance enhancement of first order three-level envelope delta sigma modulator based transmitter

Performance enhancement of first order three-level envelope delta sigma modulator based transmitter

Three-Level De-Multiplexed Dual-Branch Complex Delta-Sigma Transmitter

A Hybrid Amplitude/Time Encoding Scheme for Enhancing Coding Efficiency and Dynamic Range in Digitally Modulated Power Amplifiers

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