A5000188182- Advanced Wireless Communication Technologies
- Indoor and Outdoor Localization Technologies
- Underwater Vehicles and Communication Systems
- IoT Networks and Protocols
- Advanced MIMO Systems Optimization
- Satellite Communication Systems
- Antenna Design and Analysis
- UAV Applications and Optimization
- Wireless Communication Networks Research
- PAPR reduction in OFDM
- Antenna Design and Optimization
University of British Columbia
2020-2023
In this paper, we consider and study a cell-free massive MIMO (CF-mMIMO) system aided with reconfigurable intelligent surfaces (RISs), where large number of access points (APs) cooperate to serve smaller users the help RIS technology. We imperfect channel state information (CSI), each AP uses local estimates obtained from uplink pilots applies conjugate beamforming for downlink data transmission. Additionally, random at during both training transmission phases. This allows us eliminate need...
This work makes the preliminary contribution of studying asymptotic performance a multi-user intelligent reflecting surface (IRS) assisted-multiple-input single-output (MISO) downlink system under imperfect CSI. We first extend existing least squares (LS) ON/OFF channel estimation protocol to system, where we derive minimum mean squared error (MMSE) estimates all IRS-assisted channels over multiple sub-phases. also consider low-complexity direct (DE) scheme, BS obtains MMSE estimate overall...
This work studies the net sum-rate performance of a distributed reconfigurable intelligent surfaces (RlSs)-assisted multi-user multiple-input-single-output (MISO) downlink communication system under imperfect instantaneous-channel state information (I-CSI) to implement precoding at base station (BS) and statistical-CSI (S-CSI) design RISs phase-shifts. Two channel estimation (CE) protocols are considered for I-CSI acquisition: (i) full CE protocol that estimates all direct RISs-assisted...
Cell free (CF) massive multiple-input multiple-output (mMIMO) is a promising technology in realizing beyond fifth generation (B5G) networks. Massive deployment of access points (APs) CF-mMIMO system increases the spectral efficiency, however it also energy consumption and fronthaul requirements. Since recently reconfigurable intelligent surface (RIS) shown to be cost-effective solution improve performance wireless networks, RIS can enhance systems. In this work, we study downlink (DL) aided...
This work studies the net sum-rate performance of a distributed reconfigurable intelligent surfaces (RISs)-assisted multi-user multiple-input-single-output (MISO) downlink communication system under imperfect instantaneous-channel state information (I-CSI) to implement precoding at base station (BS) and statistical-CSI (S-CSI) design RISs phase-shifts. Two channel estimation (CE) protocols are considered for I-CSI acquisition: (i) full CE protocol that estimates all direct RISs-assisted...
Communication with unmanned aerial vehicles (UAVs) in current terrestrial networks suffers from poor signal strength due to the down-tilt of access points (APs) that are optimized serve ground users ends (GUEs). To solve this, one could tilt AP antenna upwards or allocate more power UAV. However, this negatively affects GUE downlink (DL) rates. In paper, we propose challenge using a reconfigurable intelligent surface (RIS) enhance UAV communication while preserving 3GPP-prescribed downwards...
This work studies the net sum-rate performance of a distributed reconfigurable intelligent surfaces (RISs)-assisted multi-user multiple-input-single-output (MISO) downlink communication system under imperfect instantaneous-channel state information (I-CSI) to implement precoding at base station (BS) and statistical-CSI (S-CSI) design RISs phase-shifts. Two channel estimation (CE) protocols are considered for I-CSI acquisition: (i) full CE protocol that estimates all direct RISs-assisted...
This work makes the preliminary contribution of studying asymptotic performance a multi-user intelligent reflecting surface (IRS) assisted-multiple-input single-output (MISO) downlink system under imperfect CSI. We first extend existing least squares (LS) ON/OFF channel estimation protocol to system, where we derive minimum mean squared error (MMSE) estimates all IRS-assisted channels over multiple sub-phases. also consider low-complexity direct (DE) scheme, BS obtains MMSE estimate overall...
Communication with unmanned aerial vehicles (UAVs) in current terrestrial networks suffers from poor signal strength due to the down-tilt of access points (APs) that are optimized serve ground users ends (GUEs). To solve this, one could tilt AP antenna upwards or allocate more power UAV. However, this negatively affects GUE downlink (DL) rates. In paper, we propose challenge using a reconfigurable intelligent surface (RIS) enhance UAV communication while preserving 3GPP- prescribed downwards...
In this paper, we consider and study a cell-free massive MIMO (CF-mMIMO) system aided with reconfigurable intelligent surfaces (RISs), where large number of access points (APs) cooperate to serve smaller users the help RIS technology. We imperfect channel state information (CSI), each AP uses local estimates obtained from uplink pilots applies conjugate beamforming for downlink data transmission. Additionally, random at during both training transmission phases. This allows us eliminate need...