Carrier synchronization of offset QPSK for deep space telemetry

Non-coherent Receivers for Low Data Rate Transmissions under Weak Solar Scintillation

“…In summary, the channel is modeled according to the following steps. For a given transmission band (X, Ka or S) and SEP angle, we first obtain obtain the scintillation index m following [5] and the magnitude spectrum S r (f ) following [11]. Then, we consider a uniform sampling of S r (f ) in the unit interval in N H points and obtain the correlation coefficients ρ r (i), i = 0, .…”

“…were considered: the "Solar-X" scenario refers to a transmission in X band with SEP angle equal to 1 deg, whereas the "Solar-Ka" scenario emulates a Ka band transmission with SEP angle equal to 0.5 deg. In both cases, we used the parametrization of the channel magnitude spectrum in [11] and the scintillation index was chosen according to [5].…”

“…Several works have focused on describing the scintillation index as a function of SEP angle, typically by using curve fitting with respect to real field measurements. One of the earliest models was initially proposed in [4] and later refined in [5] for X, Ka and S bands. The main conclusion from these models is that the scintillation index approximately decays as the inverse of the sinus of the SEP angle to the power of 1.55, up to a multiplicative constant that depends on the frequency band.…”

Cyclic spectrum based carrier recovery for OQPSK

“…But the loop filter is very complex. The error function used in [1] is more complex but the loop filter is quite simple. Many other methods are based on the Costas loop.…”

“…Many carrier recovery methods of OQPSK are based on PLL [1]. The researches of PLL generally focus on design of the error function and the loop filter [2].…”