User Selection and Precoding Schemes Based on Partial Channel Information for Broadcast MIMO Systems

User Selection and Precoding Schemes Based on Partial Channel Information for Broadcast MIMO Systems

Due to the large number of users and the time-varying characteristics of wireless channels, it is very tough to inform the transmitter of full channel information in real multi-user MIMO broadcast systems. On the other hand, the capacity of multi-user systems greatly depends on the knowledge of the channel at the transmitter while this is not always the case in single-user MIMO systems. In this...

channel estimation for mimo-ofdm systems

تخمین دقیق مشخصات کانال در سیستم های مخابراتی یک امر مهم محسوب می گردد. این امر به ویژه در کانال های بیسیم با ‏خاصیت فرکانس گزینی و زمان گزینی شدید، چالش بزرگی است. مقالات متعدد پر از روش های مبتکرانه ای برای طراحی و آنالیز ‏الگوریتم های تخمین کانال است که بیشتر آنها از روش های خاصی استفاده می کنند که یا دارای عملکرد خوب با پیچیدگی ‏محاسباتی بالا هستند و یا با عملکرد نه چندان خوب پیچیدگی پایینی...

Semi-Blind Channel Estimation based on subspace modeling for Multi-user Massive MIMO system

‎Channel estimation is an essential task to fully exploit the advantages of the massive MIMO systems‎. ‎In this paper‎, ‎we propose a semi-blind downlink channel estimation method for massive MIMO system‎. ‎We suggest a new modeling for the channel matrix subspace. Based on the low-rankness property, we have prposed an algorithm to estimate the channel matrix subspace. In the next step, using o...

Channel Reconstruction-Based Hybrid Precoding for Millimeter Wave Multi-User MIMO Systems

The focus of this paper is on multi-user multi-input multi-output (MIMO) transmissions for millimeter wave systems with a hybrid precoding architecture at the base-station. To enable multi-user transmissions, the base-station uses a cell-specific codebook of beamforming vectors over an initial beam alignment phase. Each user uses a user-specific codebook of beamforming vectors to learn the top-...

User Selection and Precoding Techniques for Rate Maximization in Broadcast MISO Systems