Iterative Cancellation of Non-Linear Distortion Noise in Digital Communication Systems

Abstract

In this paper, an iterative receiver that performs nonlinear distortion noise cancellation is presented. The performance is assessed for time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA) and single-carrier frequency division multiple access (SC-FDMA) waveforms. Even though a return link setup is considered, the receiver is equally applicable in the forward link, taking into account the differences in the data multiplexing and the channel. Analytical modeling of the received electrical signal-to-noise ratio (SNR) is carried out for OFDMA with one iteration of non-linear distortion noise cancellation. The performance is assessed in terms of power efficiency and spectral efficiency, where the total degradation (TD) of the received SNR in a non-linear channel is minimized. The modulation formats of the DVB-RCS2 satellite return link standard and a respective non-linear channel have been used. OFDMA shows the highest power efficiency gain of 1.1-2.5 dB with 2 iterations of non-linear noise cancellation across the different modulation orders. In SC-FDMA, the gain is in the range of 0.3-1.1 dB, while gains of 0.1-0.8 dB and 0.2-1.9 dB are presented in TDMA with 20% roll-off and 5% roll-off, respectively.Index Terms-Non-linear distortion, OFDMA, SC-FDMA, TDMA, power efficiency. 0090-6778

Estimation and cancellation of transponder distortions in satellite forward links using memory polynomials

“…In order to facilitate an efficient energy consumption onboard the satellite, it is desirable to operate the TWTA close to saturation with low OBO settings. In general, the OBO is applied to shift the power transfer towards the linear regime at the cost of a penalty in the energy efficiency, whereby the OBO is defined as the ratio between the peak output power of the amplifier and the average output power of the signal in the linear domain . In the non‐linear regime, signals from higher‐order APSK constellations are known to suffer from non‐linear distortions, described as constellation warping and symbol clustering at the input of the demodulator at the receiver .…”

“…In order to reduce the complexity of the iterative receiver, the symbol‐based equalizer with non‐linear distortion cancellation has been introduced by Dimitrov . It applies a simplified model for the received symbols after the non‐linear device and performs ML demodulation with hard decision in the cancellation loop.…”

“…whereby the OBO is defined as the ratio between the peak output power of the amplifier and the average output power of the signal in the linear domain. 13 In the non-linear regime, signals from higher-order APSK constellations are known to suffer from non-linear distortions, described as constellation warping and symbol clustering at the input of the demodulator at the receiver. 6 The received symbols can be decomposed in an In addition, the interfering component is correlated with the transmitted symbols in single-carrier digital transmission schemes, as well as in multicarrier transmission with a small number of carriers.…”

“…A symbol‐based equalizer with non‐linear distortion cancellation, introduced by Dimitrov, reduces the complexity of the receiver by using maximum likelihood (ML) demodulation with hard decision in the cancellation loop, eliminating the need of iterations with the decoder. This equalizer shows only a marginal degradation of the packet‐error rate (PER) performance in the single‐carrier satellite forward link as compared with soft information exchange with the decoder .…”

Inkjet-printed bandstop filters for interference suppression in multi-standard wireless systems

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