Downlink Physical Channel Research Articles

Hi-Loc: Hybrid Indoor Localization via Enhanced 5G NR CSI

Fifth-generation (5G) networks have been massively deployed in commerce. In addition, the new features introduced by 5G networks have been recognized to be beneficial to wireless localization. In this study, we investigate the performance of indoor localization with commercial 5G new radio (NR) signals, and the channel state information (CSI) is used for localization, which is acquired from the synchronization signal block (SSB) of the downlink physical channel. A hybrid indoor localization system named Hi-Loc has been developed. Initially, a feature enhancement module is designed to generate new features from the SSB CSI, and a data construction module is applied to prepare the dataset for subsequent localization algorithms. By introducing the dual attention mechanism deep network with convolutional neural networks (CNN) and bidirectional long short-term memory (BiLSTM), a feature-based attention mechanism and a sample-based attention mechanism are designed to extract the implicit spatial and time information of CSI, respectively. Finally, in the online stage, by applying a fully connected neural network (FCNN), the 2D coordinates are estimated based on the corresponding CSI features. We carry out indoor field tests in the typical office and corridor scenario. The results show that Hi-Loc achieves mean absolute errors of 0.65 and 1.03 m in the internal test cases of the office scenario and corridor scenario, respectively, and 1.93 and 3.10 m in the external test cases of the office scenario and corridor scenario, respectively, indicating its superiority over the compared CSI fingerprint-based methods in localization accuracy.

Implementation of Downlink Physical Channel Processing Architecture for NB-IoT Using LTE/5G Networks

The monumental success over the years, in wireless communication and mobile communication have overcome the challenges such as fading, multipath, interferences and spectrum limitations due to the advancement in the communication system with higher peak data rate with reduced latency thus most of research work are being focused from long term evolution (LTE) along with reduced delay, area and power consumption. Narrowband Internet of Things (NB-IoT) is an emerging domain with a vast range of applications. The conventional NB-IoT network uses orthogonal frequency division multiplexing (OFDM) for data transmission over the communication channel. LTE downlink physical layer has three control channels which are PCFICH, PDCCH, and PHICH uses in channel processing. The processing step involves scrambling, modulation, layer mapping, precoding and resource element mapping at the transmitter. The receiver end comprising of demapping from the source elements and detection of data occurs in physical downlink channels of LTE. 5G will make sure that, one can download an app of any MB in size at greater speed when compared with existing system. The entire scheme has been simulated using Model sim and realized in Plan Ahead Tool in Virtex 5 tool.

Adaptive spectrum‐shared association for controlled underlay D2D communication in cellular networks

This study proposes adaptive downlink association schemes for controlled device-to-device (D2D) communication in cellular networks. The proposed schemes utilise active devices under specific conditions to improve the network performance. Specifically, active devices are classified into two disjoint groups according to their individual quality of service (QoS) requirements from their base station (BS). The BS adaptively allocates downlink physical channels to meet individual QoS of devices using a minimal number of these available channels. The unused channels at each served device (in the first class) can be then utilised by that device to serve other devices from the second class, which are not served by the BS, via controlled D2D associations. Herein, D2D pair discovery as well as the conditions for establishing successful D2D association between the classified devices are treated. Furthermore, two D2D association schemes that vary in terms of their performance and implementation complexity to meet certain objectives at the device of interest are presented. The developed analytical results address the scenarios of idealised perfect and practical imperfect D2D association. Numerical results are provided to further explain the performance variations between the proposed association schemes under perfect and imperfect operation scenarios.

Realisation of 3GPP-LTE physical downlink data channel with diversity techniques using PlanAhead tool and Virtex device

A combined architecture of Long Term Evolution LTE downlink data channels with optimised transmitter and receiver is proposed in this paper. This work mainly focuses on the downlink physical channels namely Physical Downlink Shared Channel PDSCH, Physical Broadcast Channel PBCH and Physical Multicast Channel PMCH in Single Input Single Output SISO, Multiple Input Single Output MISO and Multiple Input Multiple Output MIMO configurations. The data from higher layer are scrambled, modulated, layer mapped, precoded and mapped to resource elements in the transmitter. At the receiver, demapping from resource elements, decoding, delayer mapping, demodulation and descrambling have to be done by every physical channel. Simulation of these channels is carried out using ModelSim 6.4a and synthesis and implementation are done using PlanAhead 13.4 in Viretx-5 device. Implementation results include Register Transfer Level RTL design, power estimation, resource estimation and Field Programmable Gate Array FPGA editor.

VLSI Implementation of a Fixed-Complexity Soft-Output MIMO Detector for High-Speed Wireless

This paper presents a low-complexity MIMO symbol detector with close-Maximum a posteriori performance for the emerging multiantenna enhanced high-speed wireless communications. The VLSI implementation is based on a novel MIMO detection algorithm called Modified Fixed-Complexity Soft-Output (MFCSO) detection, which achieves a good trade-off between performance and implementation cost compared to the referenced prior art. By including a microcode-controlled channel preprocessing unit and a pipelined detection unit, it is flexible enough to cover several different standards and transmission schemes. The flexibility allows adaptive detection to minimize power consumption without degradation in throughput. The VLSI implementation of the detector is presented to show that real-time MIMO symbol detection of 20 MHz bandwidth 3GPP LTE and 10 MHz WiMAX downlink physical channel is achievable at reasonable silicon cost.