Advancement in electricity is the key ingredient that can actively take part in alleviating poverty and drastically improve the socio-economic status of the people of Bangladesh. The incorporation of renewable energy sources would help the country meet the energy requirement as well as contribute positively towards building a sustainable planet. The paper has extensively discussed the potential aspects of renewable energy resources in Bangladesh and how the Internet of Things can facilitate the implementation of intermittent sources. The regulatory and socio-economic aspects of the renewable energy industry have been explored and sustainable solutions will be discussed to fast-track the process of integrating various renewable energy sources in the power grid to meet the energy demand. The paper discusses the challenges associated with the RE integration in Bangladesh’s power mix and tries to mitigate it through the IoT. Besides that, an RE map for Bangladesh along with prospective power network has also been discussed in this work.

Renewable Energy Sector in Bangladesh: The Current Scenario, Challenges and the Role of IoT in Building a Smart Distribution Grid

13.4 All-digital RF transmitter in 28nm CMOS with programmable RX-band noise shaping

In this paper, an advanced duplex scheme called cross-division duplex (XDD) is proposed to enhance uplink (UL) coverage in time division duplex (TDD) carriers by utilizing self-interference cancellation (SIC) capability at a base station. With XDD, it is possible to combine TDD’s ability to efficiently handle asymmetric UL and downlink (DL) traffic with frequency division duplex’s coverage advantage. To do so, XDD simultaneously operates UL and DL on the same TDD carrier but on different frequency resources. Such operation leads to severe interference on the received UL signal at the base station which requires two levels of SIC implementation; antenna and digital SIC. More than 50 dB of interference is removed through the antenna SIC using electromagnetic barriers between the transmitting and receiving antennas. The remaining interference is removed by the digital SIC based on estimating the non-linear channel of the circuit at the receiver baseband. It is verified by simulation and analysis that with the proposed XDD, the UL coverage can be improved by up to 2.37 times that of TDD. To check the feasibility of XDD, a Proof-of-Concept was developed where it was observed that the benefits of XDD can indeed be realized using the proposed SIC techniques.

/pdf/extending-5g-tdd-coverage-with-xdd-cross-division-duplex-38vehs3wxx.pdf

Extending 5G TDD Coverage With XDD: Cross Division Duplex

This brief deals with self-interference (SI) effects in mobile communication radio frequency (RF) transceivers. The basics of current communication standards, namely Long-Term Evolution (LTE) and 5G, are outlined with a focus on carrier aggregation (CA). RF transceivers that support frequency-division duplex (FDD) and CA variants operate multiple receivers and transmitters simultaneously. We illustrate the resulting SI problems, present suitable models for different SI categories and discuss the associated interference estimation tasks. Moreover, we explain the basic architecture of two common countermeasures: digital and mixed-signal SI cancellation.

/pdf/a-survey-on-self-interference-cancellation-in-mobile-lte-a-dpw7col8dj.pdf

A Survey on Self-Interference Cancellation in Mobile LTE-A/5G FDD Transceivers

In frequency division duplex transceivers, a part of the transmit signal leaks into the receive path due to the non-ideality of the analog duplexer. Although operating on a different frequency band, non-ideal effects in the receive path lead to self-interferences with potentially higher power level than the wanted receive signal. One option to tackle this problem is the use of adaptive filtering algorithms for interference cancellation. In this work, we discuss support vector machines (SVMs) as an alternative approach. Different to the existing methods, the proposed concept does not need a model of the type of interference. We investigate the cancellation performance of SVMs compared to a recently published nonlinear adaptive filter for a specific type of interference called the second-order intermodulation distortion. It turns out that SVMs clearly outperform the adaptive filtering approach even for the severe case of narrow allocated transmit signals and high transmit power levels.

Support Vector Machines for Self-Interference Cancellation in Mobile Communication Transceivers

This article presents a comprehensive survey of the literature on self-interference (SI) in long-term evolution advanced (LTE-A) and fifth-generation (5G) new radio transceivers and should serve the reader as a guide and starting point for further work on SI management. Current trends in cellular transceiver designs are discussed, and reasons why new technologies, such as carrier aggregation, cause potential sensitivity degradation due to self-interfering signals are highlighted. The survey provides an overview of the most common interference mechanisms and continues with a taxonomy on SI mitigation architectures by comparing the strengths and weaknesses of various techniques.

/pdf/a-survey-of-self-interference-in-lte-advanced-and-5g-new-5d1do40rkq.pdf

A Survey of Self-Interference in LTE-Advanced and 5G New Radio Wireless Transceivers

Direct-conversion transceivers are the predominating architecture in current mobile communication systems. Despite many advantages, this topology suffers from unavoidable mismatches in the analog part, which causes imbalance between the in-phase and quadrature (I/Q) component. In this paper, we present a novel fully digital, blind I/Q imbalance compensation algorithm that features extremely low computational complexity and high compensation performance for a wide range of input signal types. Different to many state-of-the-art compensation schemes, the approach is not based on a gradient descent optimization and does not require any global feedback. This simplifies the implementation at high data rates and reduces the configuration effort to a minimum. For comparison, we examine an existing method of moment-based estimator with similar properties, for which we also provide the detailed insights beyond available literature. For both algorithms, we provide a rigorous mathematical analysis, which is supported by simulations with a focus on various long-term evolution (LTE) signal types. In addition, hardware architectures, including field-programmable gate array (FPGA) verification, are presented for both algorithms.

/pdf/ultra-low-complex-blind-i-q-imbalance-compensation-2prnmn1ar2.pdf

Thomas Paireder

Papers

A Survey of Self-Interference in LTE-Advanced and 5G New Radio Wireless Transceivers

Ultra-Low Complex Blind I/Q-Imbalance Compensation