Markus Allén

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— In this article, the design and analysis of sophisticated multi-band quadrature ΣΔ modulators (QΣΔM) are addressed, offering a high-performance and easily-reconfigurable solution for the analog-to-digital (A/D) interface of cognitive radio receivers. Based on spectrum sensing information, the multi-band principle stemming from multi-stage converter(More)
In this article, the design and implementation of mixed-signal frequency synthesis for wireless communications devices are addressed. The core of the synthesizer builds on digitally synthesized tunable low-frequency I/Q tone which is then shifted to the actual radio frequency range using I/Q modulation. An efficient real-time FPGA design of the digital(More)
—This paper studies the idea and performance of cyclostationary spectrum sensing in cognitive full-duplex radios, when secondary transmission and spectrum sensing are done simultaneously at the same channel. The paper starts by briefly introducing the ideas of cognitive full-duplex radio and the cyclo-stationary spectrum sensing in the presence of(More)
—A quadrature Σ∆ analog-to-digital converter (ADC) is a promising solution for intermediate frequency digitizing software defined cognitive radio (CR) receivers because of, e.g., multiband capability and power efficiency. However, inherent coefficient mismatches between the in-phase and quadrature rails can severely damage the performance of such receiver(More)