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Physical Layer BB High-Flux Contents 16 July 2014. Igor Zayer, ESA. I. Signal Acquisition. Terminal A The center frequency shall be 281566,0 GHz ± 0.14 %
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Physical Layer BBHigh-Flux Contents16 July 2014 Igor Zayer, ESA
I. Signal Acquisition • Terminal A • The center frequency shall be 281566,0 GHz ± 0.14% • The transmit beam shall have a Left-hand Circular Polarization (LCP: where the E-vector rotates counter-clockwise as viewed from the transmitter in the direction of propagation) • During spatial acquisition, the transmit signal shall be amplitude modulated with a frequency of 1.0045 MHz +/- 200 ppm and a modulation index higher than 95%. • Terminal B • The center frequency shall be 281594,0 ± 0.14% • The transmit beam shall have a Right-hand Circular Polarization (RCP: where the E-vector rotates clockwiseas viewed from the transmitter in the direction of propagation) • During spatial acquisition, the transmit signal shall be amplitude modulated with a frequency of 1.7578 MHz +/- 200 ppm and a modulation index higher than 95%.
II. Communication Signal (1/6) • Terminal A • The center frequency shall be 281566,0 GHz • The transmit beam shall have a Left-hand Circular Polarization (LCP: where the E-vector rotates counter-clockwise as viewed from the transmitter in the direction of propagation) • Terminal B • The center frequency shall be 281594,0 GHz • The transmit beam shall have a Right-hand Circular Polarization (RCP: where the E-vector rotates clockwise as viewed from the transmitter in the direction of propagation)
II. Communication Signal (2/6) • Both Terminals • The TX laser shall be tunable within a range of +-10 GHz • The maximum laser tuning range rate shall be 120 MHz/s in communication mode • The un-modulated TX laser shall have a line width of less than 100 kHz over a time scale of 100 msec • The TX laser Relative Intensity Noise (RIN) shall be less than -30 dB in the frequency range between 0.01 Hz and 1 MHz.
II. Communication Signal (3/6) • Both Terminals • The spectral density of the RIN shall be better than given in the Figure below
II. Communication Signal (4/6) • Both Terminals • The frequency noise of the free running TX laser shall be less than the limit in Figure below • The change rate of the laser phase noise shall be below 6400 rad/s (Δφ/ Δt).
II. Communication Signal (5/6) • Both Terminals • The modulation scheme shall be Binary Phase-Shift Keying (BPSK) with Non-Return to Zero (NRZ). The nominal symbol rate shall be 2812.5 Megasymbols/sec (Msps) . • The modulating base-band spectrum of the transmit signal shall fulfill the spectral mask defined in the Figure below. This spectrum shall be generated by the following Line Product Code (LPC) as defined in Ref. ## (Coding Blue Book)
II. Communication Signal (6/6) • Both Terminals • The base-band eye-pattern shall fulfill the requirements listed in the Table and as defined by the Figure below.