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Phase-Noise EQ2440 26/3-2014

Phase-Noise EQ2440 26/3-2014. Per Zetterberg. I&Q Modulator. x. x. +. I&Q Demodulator. x. x. BP. LP. LP. With phase-noise. With noise or interference. Can leak into desired signal, when LO1 is non-ideal. SDR: Flexibility in digital => lots of E(f). Time-Domain. Phase-noise.

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Phase-Noise EQ2440 26/3-2014

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  1. Phase-NoiseEQ2440 26/3-2014 Per Zetterberg

  2. I&Q Modulator x x +

  3. I&Q Demodulator x x BP LP LP

  4. With phase-noise With noise or interference Can leak into desired signal, when LO1 is non-ideal. SDR: Flexibility in digital => lots of E(f)

  5. Time-Domain Phase-noise Modulated signal (partially known, e.g. training) Phase-noise spectrum: or Don’t be to sure of which is refered to....

  6. PLL Phase Detector Loop-filter VCO - Ref Out Noises: VCO: 1,1/f,1/f^2,1/f^3 1/N : 1, 1/f Phase detector: 1, 1/f Ref input:

  7. Model PLL Dynamics And Phase-Noise Performance Phase Detector Loop-filter VCO

  8. Phase-Noise Spectrum ADF4360 (RFX1800)

  9. OFDM Subcarrier information symbols e.g. QPSK={-1,+1,-j,+1} Cyclic prefix typically 10% Symbol time without CP. Phase-noise cause inter-carrier interference.

  10. add_phase_noise.m • Matlab function from MATLAB central. • Spectrum defined in a PSD diagram (dBc) is used as input. • The assumption is used. => Spectrum of is equal to spectrum of . • The real-valued noise is generated in the frequency-domain using FFT (Gaussian noise. Independent from bin to bin). • My question: How accurate is this model ? • My observation: Very neat function.

  11. A Novel Model for Simulation of RF Oscillator Phase Noise • Paper by Siamak Yousefi potential PhD student at KTH. • Studies problem scetched below. • Some exact mathematical treatment and some approxmiations. • Models noise close to carrier better than Leeson. • Output of integrator unstable (my observation). Thermal and flicker noise Integrator exp(j*a)

  12. For project course. • Use matlab function add_phase_noise.m. • Provide three basic settings. Good, fair and bad. • Present PLL with slides. Refer to ”Phase Locked Loops for High-Frequency Receivers and Transmitters Part 1-3” and ”Model PLL Dynamics and Phase-Noise Performance”.

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