Browsing by Author "Ahmed, Nouman"

Filter results by typing the first few letters
Now showing 1 - 4 of 4
  • A 2-5.5 GHz Beamsteering Receiver IC With 4-Element Vivaldi Antenna Array
    (2020-09) Zahra, Mahwish; Kempi, Ilia; Haarla, Jaakko; Antonov, Yury; Khonsari, Zahra; Miilunpalo, Toni; Ahmed, Nouman; Inkinen, Juha; Unnikrishnan, Vishnu; Lehtovuori, Anu; Viikari, Ville; Anttila, Lauri; Valkama, Mikko; Kosunen, Marko; Stadius, Kari; Ryynänen, Jussi
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    In this article, we present a four-element Vivaldi antenna array and beamsteering receiver IC for the fifth-generation mobile network (5G) new radio (NR). The implemented receiver utilizes a delay-based local-oscillator phase shift technique for accurate beamsteering, and it exhibits 1° to 2.4° phase tuning capability for 2-5 GHz bandwidth accordingly. On-chip delay measurement is performed with pilot signal generation and delay estimation capable of 2-ps accuracy. The IC is fabricated on 28-nm CMOS technology, it occupies an area of 1.4x1.4 mm^2, including bonding pads, and consumes 22.8 mW at 2 GHz for single-receiver path operation. The receiver demonstrates wideband over-the-air reception with the prototype antennas.
  • A 3-43ps time-delay cell for LO phase-shifting in 1.5-6.5GHz beamsteering receiver
    (2018) Antonov, Yury; Zahra, Mahwish; Stadius, Kari; Khonsari, Zahra; Ahmed, Nouman; Kempi, Ilia; Inkinen, Juha; Unnikrishnan, Vishnu; Ryynänen, Jussi
     A4 Artikkeli konferenssijulkaisussa
    This paper describes a digital-friendly passives-less time delay cell that generates programmable phase-shifts for down converting front-end in LO-based beamsteering receiver. Cell design supports 1.5–6.5GHz broadband receiver operation and cell layout occupies an area of only 15×16.5μm 2 including power supply rails and control logic. Simulated in 28nm CMOS technology, delay cell exhibits 6 distinct delay values {3, 3.5, 17, 19, 24, 43}ps consuming at most 220μW@IV.
  • Implementation of Digital Control and Communication Protocol for Low Power Medical Implants
    (2016-08-24) Ahmed, Nouman
     Sähkötekniikan korkeakoulu | Master's thesis
    Implanted electrodes at the scalp or beneath skin provides an efficient substitute to wired electrodes in order to measure frequency and seizure location for patients suffering from severe epilepsy. A efficient wireless communication system can deliver an improved set of measurement results and can assist with ease for patients. This work aims at implementation of efficient protocol to achieve wireless data transmission and to gain a digital control over communication between the medical sensor implant and the EEG monitoring device. The system is based on inductive powering and inductive coupling for implantable devices. The inductive link uses mutual inductance of two coupled coils of RFID tag and an external reader and it consumes less electrical power than conventional radio systems which also removes the need of batteries. The operation to transmit data through wireless inductive link communication comprise transmitting RFID reader signals, receiving RFID response signals and determining range of RFID implanted device. The operation is achieved by digitally controlling communication between implanted RFID tag and external reader. The implemented digital system consist of four digital blocks including a First in First Out (FIFO), a Cyclic Redundancy Check (CRC) error detection and single bit error correction block, a FMO encoder block and a state logic block. The system is implemented on XILINX Zc706 FPGA board which serves as a controller to digital inductive transceiver and is tested using UART communication between PC and implemented inductive transceiver on FPGA. The objective is to achieve high data rate and to minimize error rate in the communication to build a very high speed and high performance system. High speed enables the continuous EEG data monitoring from brain without data overlapping while error free data ensures correct data communication which is very critical in EEG signals monitoring.
  • Resilient flow control for wireless data streaming in inductively coupled medical implants
    (2020-02-01) Kempi, Ilia; Ahmed, Nouman; Hammer, Andreas; Olabode, Olaitan; Unnikrishnan, Vishnu; Kosunen, Marko; Ryynänen, Jussi
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    This paper describes the hardware implementation of a custom communication protocol tailored for low power telemetry data streaming over an inductive link. An efficient transceiver design is achieved by adapting only the essential physical layer features of a typical RFID baseband processor and optimizing the flow control logic for continuous and reliable data transfer. For the external near-field reader, we provide a logical model for receiver operation and suggest a simple forward error correction (FEC) mechanism. The benefit of FEC in the context of developed communication system is demonstrated by simulations, and projections of design scalability are also presented. The proposed communication system was implemented in 28nm CMOS process. Place-and-route (PNR) results occupy only 0.0048 mm2 of core area, and the transient simulations show a power consumption of 306 nW at 0.5 V supply and a master clock of 845.7 kHz. The implementation provides an uplink rate of 12 kbit/s, sufficient for reliable transmission of a 1-channel 1 kS/s 12-bit sample recording.