Novel Polar Coded MIMO Power Domain NOMA Scheme for 5G New Radio (NR)

The use of Polar coded Multiple Input Multiple Output Power Domain Non-Orthogonal Multiple Access (MIMO PD-NOMA) technology has the potential to greatly improve the capacity and spectral efficiency of 5G NR systems. From the on-going research, there is a combination of polar coded NOMA and Polar coded MIMO techniques are approached separately with other channel coding techniques. This paper introduces a novel approach to combine polar coded with MIMO power domain NOMA to enhance the system performance. MIMO Power Domain NOMA that utilizes polar codes for channel coding and power allocation. By combining the benefits of NOMA and MIMO, which permits multiple users to share frequency-time resources simultaneously and the MIMO employs multiple antennas to increase diversity gain and spatial multiplexing gain. The proposed scheme provides effective utilization of radio resources where the polar codes are an optimal choice for 5G NR systems due to their strong error correction capability and low complexity decoding. Successive Cancellation List -Singular Value Decomposition adaptive scaling algorithm (SCL-SVD) is proposed in the polar decoding process. The suggested method attains 6.5 dB coding gain and improved throughput of 80.34% using MATLAB simulation. The proposed model compared with the other existing model such as Power Domain NOMA (PD-NOMA), multiple input single output NOMA (miso-NOMA) and multiple input multiple output NOMA (mimo-NOMA) in terms of Bit Error Rate (BER) and Signal to Noise Ratio (SNR). This scheme has the potential for practical implementation and can play a crucial role in meeting the increasing demands of future wireless communication systems

Internal pilot insertion for polar codes

Two internal pilot insertion methods are proposed for polar codes to improve their error correction performance. The presented methods are based on a study of the weight distribution of the given polar code. The insertion of pilot bits provided a new way to control the coding rate of the modified polar code on the basis of the Hamming weight properties without sacrificing the code construction and the related channel condition. Rate control is highly demanded by 5G channel coding schemes. Two short-length polar codes were considered in the work with successive cancellation list decoding. The results showed that advantages in the range of 0.1 to 0.75 dB were obtained in the relative tolerance of the modified coded signal to the additive white Gaussian noise and fading channels at a bit error rate of 10−4. The simulation results also revealed that the performance improvements were possible with a careful insertion of the pilots. The modified polar code with pilot insertion provided performance improvement and offered the control of the coding rate without any added complexity at both the encoder and the decoder

Implementation of a low complexity structure for MIMO-GFDM receivers based on the interference cancellation technique

The emerging mobile communication systems towards an unprecedented evolution in terms of flexibility, data rate, and latency, enabling wireless networks to support applications that are typically backed by wired technologies. The next generation of mobile communication is already being discussed by the scientific community, standardization institutes, and players in the mobile communication market. The foreseen scenarios are already beginning to be outlined, anticipating that they might be even harder to achieve considering the expected increase in flexibility while supporting conflicting requirements across several applications in different verticals, besides higher data rates, broader coverage, wider frequency bands, and extreme low latency. It is clear that future mobile networks cannot rely on a single radio access network to meet all these demands. Different approaches are needed to address all requirements, but SM (Spatial Multiplexing)- MIMO (Multiple-Input Multiple-Output) schemes represent a key technology for most future wireless systems. SM-MIMO can provide the necessary bandwidth, reducing the frame duration and increasing the robustness for data with a very short life span. Furthermore, integrating SM-MIMO systems with advanced detection schemes, that leverage both diversity and multiplexing gains, can substantially boost throughput and extend coverage area. Usually, MIMO schemes are combined with OFDM (Orthogonal Frequency Division Multiplexing) to deal with double-dispersive channels, assuming that the channel coherence time is larger than the duration of the OFDM block and the channel coherence bandwidth is larger than the subcarrier bandwidth. However, OFDM presents limitations that could hinder its applications in future mobile systems. High OOB (Out-of-Band) emissions, low flexibility in terms of parameterization, and low spectral and energy efficiencies for channels with large delay profiles are some examples of these restrictions. In this sense, GFDM (Generalized Frequency Division Multiplexing) can be considered a feasible alternative. However, a challenge arises when considering non-orthogonal MIMOGFDM since conventional linear detectors exhibit higher complexity and inferior performance compared to MIMO-OFDM systems. Consequently, there is a compelling need to explore non-conventional detectors that simultaneously reduce complexity while aiming for performance enhancement. For this end, this thesis reviews fundamental concepts in linear estimation and detection techniques, providing a straightforward algorithmic description that enables complexity comparison and performance simulation. This work adapts the low complexity and low latency iterative MMSE (Minimum Mean Squared Error)- PIC (Parallel Interference Cancelation) introduced in [1], designing and simulating its performance in a practical 6G (Sixth Generation) transceiver for the eRAC (Enhanced Remote Area Communications) scenario, a challenging task assuming a non-orthogonal GFDM waveform. The final results, presented in this work, show that MIMO-GFDM is an interesting approach to deal with very contrasting and challenging requirements in mobile networks. As a result, the pragmatic assessment of theoretical concepts, validated through simulations, is interesting to the scientific community, as it demonstrates the potential improvements that the adoption of a new technology can achieve. Furthermore, this work provides a versatile computational model, which is an essential tool and also a reliable reference for hardware development and performance evaluation.Os sistemas de comunicação móvel emergentes estão evoluindo de forma sem precedentes em termos de flexibilidade, taxa de dados e latência, permitindo que as redes sem fio suportem aplicações que normalmente são sustentadas por tecnologias cabeadas. A próxima geração de comunicação móvel já está sendo discutida pela comunidade científica, institutos de padronização e pelos atores do mercado de comunicação móvel. Os cenários previstos já estão começando a ser delineados, antecipando que podem ser ainda mais difíceis de alcançar, considerando o aumento esperado na flexibilidade, enquanto suportam requisitos conflitantes em várias aplicações e em diferentes setores, além de taxas de dados mais altas, maior cobertura, bandas de frequência mais amplas e latência extremamente baixa. É claro que as futuras redes móveis não podem depender de uma única rede de acesso sem fio para satisfazer a todas essas demandas. Abordagens diferentes são necessárias para atender a todos os requisitos, mas os esquemas SM-MIMO representam uma tecnologia chave para a maioria dos futuros sistemas sem fio. O SMMIMO pode fornecer a vazão necessária, reduzindo a duração do quadro e aumentando a robustez para informações com uma vida útil muito curta. Além disso, integrar sistemas SM-MIMO com esquemas de detecção avançados, que aproveitam tanto o ganho de diversidade quanto o de multiplexação, pode aumentar substancialmente a taxa de transferência e estender a cobertura da rede móvel. Normalmente, os esquemas MIMO são combinados com OFDM para lidar com canais duplamente dispersivos, assumindo que o tempo de coerência do canal é maior que a duração do bloco OFDM e a largura de banda de coerência do canal é maior que a largura de banda de uma subportadora. No entanto, o OFDM apresenta limitações que podem dificultar suas aplicações em sistemas móveis futuros. Altas emissões fora da banda, baixa flexibilidade em termos de parametrização e baixa eficiência espectral e energética para canais com longos perfis de atraso são alguns exemplos dessas restrições. Nesse sentido, o GFDM pode ser considerado uma alternativa viável. Entretanto, há um grande desafio ao uso do MIMO GFDM não ortogonal uma vez que os detectores lineares convencionais apresentam maior complexidade e desempenho inferior em comparação com os sistemas MIMO OFDM. Como resultado, há uma necessidade premente de explorar detectores não convencionais que reduzam a complexidade ao mesmo tempo em que buscam melhorias de desempenho. Para esse fim, esta tese revisa conceitos fundamentais sobre técnicas de estimação linear e detecção, fornecendo uma descrição algorítmica direta que permite a comparação de complexidade e simulação de desempenho. Este trabalho adapta o MMSE-PIC iterativo de baixa complexidade e baixa latência introduzido em [1], projetando e simulando seu desempenho em um transceptor 6G prático para o cenário eRAC, uma tarefa desafiadora assumindo que a forma de onda GFDM não é ortogonal. Os resultados finais apresentados neste trabalho mostram que o MIMO-GFDM é uma abordagem interessante para lidar com os requisitos contrastantes e desafiadores das futuras redes móveis. Logo, a avaliação pragmática de conceitos teóricos, validada por meio de simulações, é de interesse da comunidade acadêmica, pois demonstra as potenciais melhorias que a adoção de uma nova tecnologia pode alcançar. Além disso, esta tese fornece um modelo computacional versátil, uma ferramenta essencial, e também uma referência confiável, para o desenvolvimento de hardware e avaliação de desempenho

Fifty Years of Noise Modeling and Mitigation in Power-Line Communications.

Building on the ubiquity of electric power infrastructure, power line communications (PLC) has been successfully used in diverse application scenarios, including the smart grid and in-home broadband communications systems as well as industrial and home automation. However, the power line channel exhibits deleterious properties, one of which is its hostile noise environment. This article aims for providing a review of noise modeling and mitigation techniques in PLC. Specifically, a comprehensive review of representative noise models developed over the past fifty years is presented, including both the empirical models based on measurement campaigns and simplified mathematical models. Following this, we provide an extensive survey of the suite of noise mitigation schemes, categorizing them into mitigation at the transmitter as well as parametric and non-parametric techniques employed at the receiver. Furthermore, since the accuracy of channel estimation in PLC is affected by noise, we review the literature of joint noise mitigation and channel estimation solutions. Finally, a number of directions are outlined for future research on both noise modeling and mitigation in PLC

Efficient systematic turbo polar decoding based on optimized scaling factor and early termination mechanism

In this paper, an efficient early termination (ET) mechanism for systematic turbo-polar code (STPC) based on optimal estimation of scaling factor (SF) is proposed. The gradient of the regression line which best fits the distance between a priori and extrinsic information is used to estimate the SF. The multiplication of the extrinsic information by the proposed SF presents effectiveness in resolving the correlation issue between intrinsic and extrinsic reliability information traded between the two typical parallel concatenated soft-cancellation (SCAN) decoders. It is shown that the SF has improved the conventional STPC by about 0.3 dB with an interleaver length of 64 bits, and about 1 dB over the systematic polar code (SPC) at a bit error rate (BER) of . A new scheme is proposed as a stopping criterion, which is mainly based on the estimated value of SF at the second component decoder and the decoded frozen bits for each decoding iteration. It is shown that the proposed ET results in halving the average number of iterations (ANI) without adding considerable complexity. Moreover, the modified codes present comparable results in terms of BER to the codes that utilize fix number of iterations