Dataset for Sixty Years of Coherent Versus Non-coherent Tradeoffs and the Road from 5G to Wireless Futures

This is the dataset for the accepted paper (2 Dec 2019) Chao Xu, Naoki Ishikawa, Rakshith Rajashekar, Shinya Sugiura, Robert G. Maunder, Zhaocheng Wang, Lie-Liang Yang and Lajos Hanzo, &quot;Sixty Years of Coherent Versus Non-coherent Tradeoffs and the Road from 5G to Wireless Futures&quot; IEEE Access</span

Bit-Interleaved Coded Energy-Based Modulation with Iterative Decoding

This paper develops a low-complexity near-optimal non-coherent receiver for a multi-level energy-based coded modulation system. Inspired by the turbo processing principle, we incorporate the fundamentals of bit-interleaved coded modulation with iterative decoding (BICM-ID) into the proposed receiver design. The resulting system is called bit-interleaved coded energy-based modulation with iterative decoding (BICEM-ID) and its error performance is analytically studied. Specifically, we derive upper bounds on the average pairwise error probability (PEP) of the non-coherent BICEM-ID system in the feedback-free (FF) and error-free feedback (EFF) scenarios. It is revealed that the definition of the nearest neighbors, which is important in the performance analysis in the FF scenario, is very different from that in the coherent BICM-ID counterpart. The analysis also reveals how the mapping from coded bits to energy levels influences the diversity order and coding gain of the BICEM-ID systems. A design criterion for good mappings is then formulated and an algorithm is proposed to find a set of best mappings for BICEM-ID. Finally, simulation results corroborate the main analytical findings

Desenho de pré-codificadores e combinadores para comunicações multiutilizador assistidas por modulações de índice em sistemas pós 5G

Considerando os avanços tecnológicos das últimas décadas, espera-se que a próxima geração de comunicações sem fios siga a tendência de um aumento significativo da robustez do sistema, da eficiência espectral (SE) e da eficiência energética (EE). Atualmente na era do pós-5G, os esquemas de "Multiple Input, Multiple Output" (MIMO) baseados em modulações espaciais generalizadas (GSM) bem como noutras modulações de índices (IM), têm sido amplamente considerados como potenciais técnicas candidatas para as redes sem fios. Esta dissertação tem como objetivo desenhar e estudar um sistema MIMO para comunicações multiutilizador integrando símbolos GSM e símbolos de modulação de índices generalizada no espaço-frequência (GSFIM). Numa primeira parte estuda-se um sistema MIMO multiutilizador, em que uma estação base (BS) transmite símbolos GSM pré-codificados para vários recetores. Na abordagem GSM adotada, múltiplas antenas transmitem simultaneamente diferentes símbolos M-QAM de alto nível, até M =1024. O pré-codificador é desenvolvido de modo a remover interferências entre utilizadores enquanto um algoritmo iterativo baseado no "alternating direction method of multipliers" (ADMM) é aplicado no recetor para realizar a deteção GSM de um único utilizador. Os resultados mostram que a abordagem GSM MU-MIMO apresentada é capaz de explorar eficazmente um grande número de antenas de transmissão implantadas no transmissor e também proporcionar ganhos de desempenho sobre esquemas convencionais MU-MIMO com eficiências espectrais idênticas. Numa segunda parte, introduz-se uma nova dimensão (para além do espaço), a frequência. Estuda-se assim o comportamento dos recetores MMSE e OB-MMSE, num sistema MIMO baseado em GSFIM. Os resultados mostram que o sistema GSFIM MUMIMO explora de forma competente as comunicações com grande número de antenas/sub-portadoras, apresentando melhores desempenhos quando usada com um recetor OB-MMSE.Considering the technological advances of the last decades, the next generation of wireless communications is expected to follow the trend of a significant increase in system robustness, spectral efficiency (SE) and energy efficiency (EE). Today in the post5G era, Multiple Input, Multiple Output (MIMO) schemes based on generalised spatial modulations (GSM) as well as other index modulations (IM) have been widely considered as potential candidate techniques for wireless networks. This dissertation aims to design and study a MIMO system for multi-user communications integrating GSM symbols and generalised space-frequency index modulation (GSFIM) symbols. In a first part, a multi-user MIMO system is studied, in which a base station (BS) transmits pre-coded GSM symbols to several receivers. In the GSM approach adopted, multiple antennas transmit different high-level M-QAM symbols simultaneously, up to M =1024. The precoder is designed to remove interference between users while an iterative algorithm based on the alternating direction method of multipliers (ADMM) is applied to the receiver to perform single user GSM detection. The results show that the GSM MU-MIMO approach presented is capable of effectively exploiting a large number of transmission antennas deployed on the transmitter and also provides desempenho gains over conventional MU-MIMO schemes with identical spectral efficiencies. In a second part, a new dimension (beyond space) is introduced, frequency. The behaviour of MMSE and OB-MMSE receivers in a GSFIM-based MIMO system is thus studied. The results show that the GSFIM MU-MIMO system competently exploits communications with large numbers of antennas/sub-carriers and performs better when used with an OB-MMSE receiver

Sixty years of coherent versus non-coherent tradeoffs and the road from 5G to wireless futures

Sixty years of coherent versus non-coherent tradeoff as well as the twenty years of coherent versus non-coherent tradeoff in Multiple-Input Multiple-Output (MIMO) systems are surveyed. Furthermore, the advantages of adaptivity are discussed. More explicitly, in order to support the diverse communication requirements of different applications in a unified platform, the 5G New Radio (NR) offers unprecedented adaptivity, abeit at the cost of a substantial amount of signalling overhead that consumes both power and the valuable spectral resources. Striking a beneficial coherent versus non-coherent tradeoff is capable of reducing the pilot overheads of channel estimation, whilst relying on low-complexity detectors, especially in high-mobility scenarios. Furthermore, since energy-efficiency is of salient importance both in the operational and future networks, following the powerful Index Modulation (IM) philosophy, we conceive a holistic adaptive philosophy striking the most appropriate coherent/non-coherent, single-/multiple-antenna and diversity/multiplexing tradeoffs, where the number of RF chains, the Peak-to-Average Power Ratio (PAPR) of signal transmission and the maximum amount of interference tolerated by signal detection are all taken into account. We demonstrate that this intelligent triple-fold adaptivity offers significant benefits in next-generation applications of mmWave and Terahertz solutions, in space-air-ground integrated networks, in full-duplex techniques and in other sophisticated channel coding assisted system designs, where powerful machine learning algorithms are expected to make autonomous decisions concerning the best mode of operation with minimal human intervention