Channel estimation based on low‐complexity hierarchical codebook design for millimeter‐wave MIMO systems

Abstract

Millimeter-wave bands (mmWave) are considered as a strong candidate for achieving high-quality communication links for the future outdoor cellular systems to overcome the spectrum congestion problem. Due to the extremely high path loss in mmWave band, large antenna arrays at both the transmitter and receiver are necessary. Hybrid beamforming architectures are used to exploit the potential array gain with several RF chains, which poses a problem of complexity when estimating the mmWave channel. To address the challenge of this hardware complexity, we propose in this paper an approach to design a multiresolution hierarchical codebook to meet parallel multistream data based on the physical design via hybrid analog/digital architecture with low complexity, i.e., 2-bit phase state and few numbers of RF chains. The simulation results verify that our proposed method to design the codebook has better design performance of beams and can achieve higher average spectral efficiency gains of channel estimation compared to the one based on high hardware complexity.hybrid beamforming, millimeter wave communications, MIMO, multiresolution hierarchical codebook design, orthogonal matching pursuit, parallel multistream data | INTRODUCTIONDue to the intensive evolution of the internet and the huge interconnected networks, fifth-generation and beyond (5G) is the next generation of cellular networks that will be enabling the collection and exchange of information and data globally between people, communities, and more importantly, businesses, 1 thanks to leading applications, such as internetof-things (IoT), 2 ultra-high-definition (UHD) 3D video streaming, cloud-based services, and augmented reality. 3 However, to enhance the communication of these applications, 5G cellular networks must address six challenges that are not effectively addressed by fourth-generation (4G), i.e., higher capacity, higher data rate, lower end to end latency, massive device connectivity, reduced cost, and consistent quality of experience provisioning. 4 To accommodate these challenges, millimeter-wave (mmWave) communication is a promising technology for 5G-and-beyond mobile cellular networks, as well as for emerging Gbps-speed Wi-Fi networks based on the IEEE 802.11ad and draft IEEE 802.11ay standards. 5 On the other hand, one of the challenges of using mmWave frequencies to provide outdoor coverage in a cellular system is the increased path loss encountered at these frequencies. 6 For this reason, to overcome the increased path losses, narrow-beam communications powered by multiinput multioutput (MIMO) systems are typically required. In the mmWave MIMO system, to solve the dilemma of hardware complexity and system performance, hybrid analog/digital

Joint Hybrid Precoding and Combining Design Based Multi-Stage Compressed Sensing Approach for mmWave MIMO Channel Estimation

“…On the other hand, despite the blessing ability of the CS reconstruction approach to recover the high-dimension channels, beam training is the primordial step in the sparse mmWave channel estimation process as a spatial searching mechanism, where the estimation performance is based on the design quality of beams and their selection strategies [16]. To avoid exhaustive beam training, the authors in [17]- [20] proposed an adaptive CS algorithm with a predesigned multi-resolution hierarchical codebook for developing multilayer beam selection strategies. For adaptive CS-based channel estimation methods, the hybrid precoding problem is formulated as an Euclidean norm-minimization between the established precoder from the hierarchical codebook at each stage and predefined analog beam set to design the analog and digital precoders.…”

“…Unfortunately, this method does not provide uniform performance across a broad range of angles [22]. In [20], an adaptive CS-based mmWave channel estimation algorithm using parallel beams powered by orthogonal sequences are developed to generate narrow multiresolution beams with low complexity and without power allocation for reducing the complexity of hybrid architecture. Nevertheless, the computational complexity of the designed multi-resolution codebooks increases linearly with the number of dominant channel paths.…”