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- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 9th Advanced Satellite Multimedia Systems Conference and the 15th Signal Processing for Space Communications Workshop (ASMS/SPSC) - Berlin (2018.9.10-2018.9.12)] 2018 9th Advanced Satellite Multimedia Systems Conference and the 15th Signal Processing for Space Communications Workshop (ASMS/SPSC) - A Design Method of Cognitive Overlay Links for Satellite Communications
摘要： In this paper, we present a method to design cognitive overlay links for satellite communications, in order to allow the primary and the cognitive users to transmit concurrently while using efficiently the available power resources. By means of trellis shaping based dirty paper coding (DPC) and superposition techniques, numerous schemes are investigated in various realistic scenarios, and different trade-offs between power efficiency vs complexity are made. By simulations, we first show that we are able to design schemes where the primary user bit error rate (BER) is maintained as in the absence of the cognitive user interference. Secondly, thanks to trellis precoding and an appropriate constellation expansion, we show that the BER of the cognitive user can be made within 1dB of corresponding the Gaussian channel BER.
关键词： Trellis Precoding,Satellite Communications,Flexible Payloads,Cognitive Radio,Dirty Paper Coding,Overlay Paradigm
更新于2025-09-11 14:15:04
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[IEEE 2017 IEEE International Conference on Computational Intelligence and Computing Research (ICCIC) - Coimbatore, India (2017.12.14-2017.12.16)] 2017 IEEE International Conference on Computational Intelligence and Computing Research (ICCIC) - Multiuser Visible Light Communication System For Reliable Wireless Communication
摘要： Visible Light Communication (VLC) is evolving likewise a guaranteeing act on give pervasive remote association. In this paper, we study an indoor multiuser Visible Light Communication framework can substantially increase the achievable bit rate of Adaptively Modulated Optical Orthogonal Frequency-Division Multiplexing (AMO-OFDM) system and has the ability to maximise data throughput by adjusting the number of bits per subcarrier based on the set of subcarrier's channel Gain to Noise Ratio (GNR). For each subcarrier resolved alongside OFDM, those comparing precoding grids will be in the recurrence area to eradicate multiuser viewed as obstruction. VLC is one of the promising candidates because of its features of non-licensed channels, high bandwidth and low power consumption. As a visible light source can be used both for illumination and communication, therefore, it saves the extra power that is required in RF communication. The revolution in the field of solid state lighting leads to the replacement of florescent lamps by Light Emitting Diodes (LEDs) which further motivates the usage of VLC.The modulation bandwidth of white emanation is about ～2MHz.
关键词： VLC (Visible Light Communication),Multiple transmitter and receiver links,MIMO (Multiple Input Multiple Output),OFDM (Orthogonal Frequency Division Multiplexing),MMSE (Minimum Mean-Squared Error),Precoding
更新于2025-09-10 09:29:36
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Hybrid Precoding with Partially Connected Structure for mmWave Massive MIMO OFDM: A Parallel Framework and Feasibility Analysis
摘要： Hybrid precoding, a combination of digital and analog precoding, is an alternative to traditional precoding methods in massive MIMO systems with large number of antenna elements and has shown promising results recently. In this work, we implement a parallel framework to make hybrid precoding competitive in fast-fading environments. A low-complexity algorithm which exploits the block diagonal phase only nature of the analog precoder in a partially connected structure is proposed to arrive at a hybrid precoding solution for a multi-carrier single-user system using orthogonal frequency division multiplexing (OFDM). The original problem is broken down into two subproblems of finding the magnitude and the phase components which are solved independently. A per-RF chain power constraint is introduced instead of the sum power constraint over all antennas which is much more practical in real systems. An alternating version of the same algorithm is proposed for increased spectral-efficiency gains. Complexity and run-time analysis demonstrate the advantage of the proposed algorithm over existing hybrid precoding schemes for partially connected structure in an OFDM setting. Simulation results reveal certain insights about the partially connected structure and the trade-offs that have to be made to make it workable in a real wideband system.
关键词： partially connected structure,mmWave,massive MIMO,per-RF chain power constraint,Hybrid precoding,OFDM
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE 5G World Forum (5GWF) - Silicon Valley, CA (2018.7.9-2018.7.11)] 2018 IEEE 5G World Forum (5GWF) - Millimeter Wave Massive MIMO with Alamouti Code and Imperfect Channel State Information
摘要： Massive MIMO is one of the technologies considered in 5G to provide a much higher capacity without requiring more wireless spectrum. Because of the congestion in the radio frequency spectrum below 6 GHz, the millimeter Wave (mmWave) band has increasingly become more attractive to researchers since it offers a much larger unused bandwidth. However, the higher path loss at mmWave frequencies and the poor scattering nature of the mmWave channel (fewer paths exist) represent a challenge for communications. A hybrid beamforming technique with large antenna arrays and the Alamouti coding scheme are used in this paper to improve the performance of a single-user mmWave massive MIMO system. When perfect Channel State Information (CSI) is not available at the Base Station (BS), computer simulations have shown that a gain of 20 dB or more can be achieved by using the Alamouti code compared to the system with hybrid beamforming only, and more importantly, the error probability does not level off.
关键词： hybrid precoding and combining,mmWave communication,Massive MIMO,Alamouti Code
更新于2025-09-09 09:28:46
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[IEEE 2018 10th International Conference on Wireless Communications and Signal Processing (WCSP) - Hangzhou, China (2018.10.18-2018.10.20)] 2018 10th International Conference on Wireless Communications and Signal Processing (WCSP) - Achievable Rate of Indoor THz Communication Systems with Finite-Bit ADCs
摘要： In this paper, the achievable rate of the downlink terahertz (THz) communication systems equipped with finite-bit analog-to-digital converters (ADCs) at user sides is investigated. Considering the array of subarray antenna structure, the hybrid precoding with the maximum ratio transmission (MRT) and zero-forcing (ZF) precoding are applied at the baseband. The closed-form expression of the lower bound of the achievable rate is derived when the number of subarray antennas goes to infinity. It is shown that the coarse quantization distortion cannot be ignored in large antenna subarray regime. On the other hand, the rate loss caused by the phase uncertainties can be negligible in large subarray antenna regime. Overall, the impact of quantized receivers on the performance of indoor THz communication systems is characterized.
关键词： finite-bit ADCs,hybrid precoding,Terahertz communication,phase uncertainties,achievable rate
更新于2025-09-04 15:30:14
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Hybrid Beamforming Design for Full-Duplex Millimeter Wave Communication
摘要： Harnessing the abundant availability of spectral resources at millimeter wave (mmWave) frequencies is an attractive solution to meet the escalating data rate demands. Additionally, it has been shown that full-duplex (FD) communication has the potential of doubling the bandwidth efficiency. However, the presence of significant residual self-interference (SI), which is especially more pronounced at mmWave frequencies because of the non-linearities in the hardware components, erodes the full potential of FD in practice. Conventionally, the residual SI is canceled in the baseband using digital processing with the aid of a transmit precoder. In this work, we propose a hybrid beamforming design for FD mmWave communications, where the SI is canceled by the joint design of beamformer weights at the radio-frequency (RF) and the precoder as well as combiner in the baseband. Our proposed design preserves the dimensions of the transmit signal, while suppressing the SI. We demonstrate that our joint design is capable of reducing the SI by upto 30 dB, hence performing similarly to the interference-free FD system while being computationally efficient. Our simulation results show that the proposed design significantly outperforms eigen-beamforming.
关键词： Beamforming,Millimeter Wave,Hybrid Precoding,MIMO,Full-Duplex
更新于2025-09-04 15:30:14
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Precoding Design for Full-Duplex Transmission in Millimeter Wave Relay Backhaul
摘要： As the amount of user equipment and massive volumes of data continue to increase, high data rate requirements remain a major challenge, particularly in cellular networks. In networks composed of small cells, applying full-duplex (FD) millimeter wave (mmWave) wireless backhauls is a more effective and convenient approach than utilizing conventional optical fiber links. The mmWave communication technology is promising for future wireless communications due to its considerable available bandwidth, which is the basis of a high transmission rate. However, the short wavelength of mmWave leads to high propagation loss and shortens the transmission distance of the system. FD relaying can expand the coverage of the base station and achieve higher spectral efficiency than half-duplex (HD) transmission. However, the residual self-interference (SI) may degrade the performance of FD. The combination of mmWave and FD technologies compensates for the high path loss and realizes efficient transmission. In this paper, we consider an FD mmWave relay backhaul system and the SI of FD communication. We first propose an FD SI channel model in the mmWave band, which is composed of two parts: line-of-sight (LOS) SI and non-line-of-sight (NLOS) SI. According to the special mmWave MIMO structure limitation, two SI cancellation precoding algorithms are proposed to eliminate the SI in the system and achieve high spectral efficiency. The decoupled analog-digital algorithm eliminates the SI by utilizing the zero space of the channel, and the enhanced algorithm achieves higher performance. The spectral efficiency of the subconnected structure is analyzed. With appropriate performance loss, the simplified structure achieves significantly low configuration complexity.
关键词： precoding,Millimeter wave,Full-duplex,Relay,Self-interference
更新于2025-09-04 15:30:14