New modified Saleh models for memoryless nonlinear power amplifier behavioural modelling

O’Dróma, Máirtín; Meza, Serban; Lei, Chi‐Un

doi:10.1109/lcomm.2009.12.0902222

Cited by 14 publications

(15 citation statements)

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“…The crosstalk effect is simulated by coupling the signal in each RF path to its adjacent paths with 20 dB attenuation. The PA input and output are assumed to obey the Saleh model with parameters α a = 2, β a = 2.2, α φ = 2, and β φ = 1 [15]. The center frequency is set to 3.5 GHz and the baseband bandwidth to 10 MHz.…”

Section: A Simulation Resultsmentioning

confidence: 99%

A Digital Predistortion Scheme Exploiting Degrees-of-Freedom for Massive MIMO Systems

Yao

Sohul

Nealy

et al. 2018

2018 IEEE International Conference on Communications (ICC)

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The primary source of nonlinear distortion in wireless transmitters is the power amplifier (PA). Conventional digital predistortion (DPD) schemes use high-order polynomials to accurately approximate and compensate for the nonlinearity of the PA. This is not practical for scaling to tens or hundreds of PAs in massive multiple-input multiple-output (MIMO) systems. There is more than one candidate precoding matrix in a massive MIMO system because of the excess degrees-of-freedom (DoFs), and each precoding matrix requires a different DPD polynomial order to compensate for the PA nonlinearity. This paper proposes a low-order DPD method achieved by exploiting massive DoFs of next-generation front ends. We propose a novel indirect learning structure which adapts the channel and PA distortion iteratively by cascading adaptive zero forcing precoding and DPD. Our solution uses a 3rd order polynomial to achieve the same performance as the conventional DPD using an 11th order polynomial for a 100×10 massive MIMO configuration. Experimental results show a 70% reduction in computational complexity, enabling ultra-low latency communications.

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Section: A Simulation Resultsmentioning

confidence: 99%

A Digital Predistortion Scheme Exploiting Degrees-of-Freedom for Massive MIMO Systems

Yao

Sohul

Nealy

et al. 2018

2018 IEEE International Conference on Communications (ICC)

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“…The input-output characteristics of several typologies of high-power amplifiers (HPAs) are available in the literature [15], [17], [25]- [28], including the amplitude-to-amplitude (AM-AM) and the amplitude-to-phase (AM-PM) effects. Moreover, analytical models are available for describing the distortion effects of the HPAs, such as Saleh model [29] for traveling-wave-tube amplifiers (TWTAs) and a modified version [30] for solid state power amplifiers (SSPAs). To model such non-linear effects, we can write in polar coordinates the input signal to the HPA on the generic i-th RF chain of the transmitter as 2 :…”

Section: A Non-linear Amplification Stagementioning

confidence: 99%

Symbol-Level Precoding for the Nonlinear Multiuser MISO Downlink Channel

Spano

Alodeh

Chatzinotas

et al. 2018

IEEE Trans. Signal Process.

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This paper investigates the problem of the interference among multiple simultaneous transmissions in the downlink channel of a multi-antenna wireless system. A symbol-level precoding scheme is considered, in order to exploit the multiuser interference and transform it into useful power at the receiver side, through a joint utilization of the data information and the channel state information. In this context, this paper presents novel strategies which exploit the potential of symbollevel precoding to control the per-antenna instantaneous transmit power. In particular, the power peaks amongst the transmitting antennas and the instantaneous power imbalances across the different transmitted streams are minimized. These objectives are particularly relevant with respect to the non-linear amplitude and phase distortions induced by the per-antenna amplifiers, which are important sources of performance degradation in practical systems. More specifically, this work proposes two different symbol-level precoding approaches. A first approach performs a weighted per-antenna power minimization, under Qualityof-Service constraints and under a lower bound constraint on the per-antenna transmit power. A second strategy performs a minimization of the spatial peak-to-average power ratio, evaluated amongst the transmitting antennas. Numerical results are presented in a comparative fashion to show the effectiveness of the proposed techniques, which outperform the state of the art symbol-level precoding schemes in terms of spatial peak-toaverage power ratio, spatial dynamic range, and symbol-errorrate over non-linear channels.

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“…In this model, f A (·) is the amplitude-to-amplitude conversion function which specifies the amplitude of the RF signal at the output of the PA. f Φ (·) further determines the nonlinear phase shift at the output which is a function of the input amplitude. Well-known analytic formulations for f A (·) and f Φ (·) are given by Saleh's model [11], [12] in which…”

Section: A System Configurationmentioning

confidence: 99%

RLS Precoding for Massive MIMO Systems with Nonlinear Front-End

Bereyhi

Asaad

Müller

et al. 2019

2019 IEEE 20th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC)

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To keep massive MIMO systems cost-efficient, power amplifiers with rather small output dynamic ranges are employed. They may distort the transmit signal and degrade the performance. This paper proposes a distortion aware precoding scheme for realistic scenarios in which RF chains have nonlinear characteristics. The proposed scheme utilizes the method of regularized least-squares (RLS) to jointly compensate the channel impacts and the distortion imposed by the RF chains.To construct the designed transmit waveform with low computational complexity, an iterative algorithm based on approximate message passing is developed. This algorithm is shown to track the achievable average signal distortion of the proposed scheme tightly, even for practical system dimensions. The results demonstrate considerable enhancement compared to the state of the art.

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New modified Saleh models for memoryless nonlinear power amplifier behavioural modelling

Cited by 14 publications

References 0 publications

A Digital Predistortion Scheme Exploiting Degrees-of-Freedom for Massive MIMO Systems

A Digital Predistortion Scheme Exploiting Degrees-of-Freedom for Massive MIMO Systems

Symbol-Level Precoding for the Nonlinear Multiuser MISO Downlink Channel

RLS Precoding for Massive MIMO Systems with Nonlinear Front-End

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