Browsing by Author "Gomes, Rodolfo"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- A Software-Defined Radio for Future Wireless Communication Systems at 60 GHzPublication . Gomes, Rodolfo; Duarte, Luis; Ribeiro, Carlos; Caldeirinha, RafaelThis paper reports on a complete end-to-end 5G mmWave testbed fully reconfigurable based on a FPGA architecture. The proposed system is composed of a baseband/low-IF processing unit, and a mmWave RF front-end at both TX/RX ends. In particular, the baseband unit design is based on a typical agile digital IF architecture, enabling on-the-fly modulations up to 256-QAM. The real-time 5G mmWave testbed, herein presented, adopts OFDM as the transmission scheme waveform, which was assessed OTA by considering the key performance indicators, namely EVM and BER. A detailed overview of system architecture is addressed together with the hardware considerations taken into account for the mmWave testbed development. Following this, it is demonstrated that the proposed testbed enables real-time multi-stream transmissions of UHD video content captured by nine individual cameras, which is in fact one of the killing applications for 5G.
- A mm Wave solution to provide wireless Augmented Reality in classroomsPublication . Gomes, Rodolfo; Sismeiro, Luis; Ribeiro, Carlos; Sanchez, Manuel G.; Hammoudeh, Akram; Caldeirinha, Rafael F. S.This paper presents a very high throughput wireless data transmission solution for Augmented Reality (AR) Head Mounted Devices (HMDs) in the 60 GHz band. Its feasibility is assessed in an Orthogonal Frequency Division Multiplexing (OFDM) downlink communication towards five User Equipment (UE) devices, placed at different locations inside an indoor classroom environment scenario. Key Performance Indicators (KPIs) as Error Vector Magnitude (EVM), Signal-to-Noise Ratio (SNR), and path loss are considered for Quality of Service (QoS) assessment. Experimental results demonstrate the reliability of the proposed mmWave system, where a data rate of 312.5 Mbps is achieved over distances of 1, 2.4 and 4.1 m, regardless the UE position.
- Towards 5G : performance evaluation of 60 GHz UWB OFDM communications under both channel and RF impairmentsPublication . Gomes, Rodolfo; Hammoudeh, Akram; Caldeirinha, Rafael F. S.; Al-Daher, Zaid; Fernandes, Telmo; Reis, JoãoDetailed analysis on the impact of RF and channel impairments on the performance of Ultra-Wideband (UWB) wireless Orthogonal Frequency Division Multiplexing (OFDM) systems based on the IEEE 802.15.3c standard, for high data-rate applications using the 60 GHz millimetre frequency band is presented in this paper. This frequency band, due to the large available bandwidth is very attractive for future and 5G wireless communication systems. The usage of OFDM at millimetre-wave (mmWaves) frequencies is severely affected by non-linearities of the Radio Frequency (RF) front-ends. The impact of impairments is evaluated, in terms of some of the most important key performance indicators, including spectral efficiency, power efficiency, required coding overhead and system complexity, Out-Of-Band Emissions (OOBEs), Bit Error Rate (BER) target and Peak Signal-to-Noise Ratio (PSNR). Additionally, joint distortion effects of coexisting Phase-Noise (PN), mixer IQ imbalances and Power Amplifier (PA) non-linearities, on the performance degradation of a mmWave radio transceiver, combined with various multipath fading channels, are investigated. Subsequently, the power efficiency of the system is evaluated by estimating values of the PA Output-Power-Backoff (OBO) needed to meet the requirements for the Transmit Spectrum Mask (TSM) and BER target. Finally, a comparison of the system overall performance between uncoded and coded OFDM systems combined with Quadrature Amplitude Modulations (16 and 64 QAM) and its maximum operable range are evaluated by transmitting a Full HD uncompressed video frame under five different RF impairment conditions over a typical LOS kiosk 60 GHz IEEE channel model.