Study Of Partial-Band Detection Of Frequency-Hopped Signals
Paper presents comparative theoretical study of performances of alternative schemes for partial-band detection of frequency-hopped signals.
Levitt, Barry K.↗
Engineering topics
Levitt, Barry K.
Publications and source records attributed to Levitt, Barry K..
Optimum Detection Of Slow-Frequency-Hopping Signals
Two papers present theoretical analyses of various schemes for coherent and noncoherent detection of M-ary-frequency-shift-keyed (MFSK) signals with slow frequency hopping. Special attention focused on continuous-phase-modulation (CPM) subset of SFH/MFSK signals, for which frequency modulation such carrier phase remains continuous (albeit unknown) during each hop.
Levitt, Barry K.↗
Hop Timing Estimation for Noncoherent Frequency-Hopped
The optimum hop timing estimator (based on likelihood-ratio (LR)) theory is derived for noncoherent slow and fast frequency-hopped M-FSK intercept receivers.
frequency-hopped↗
Rain compensation algorithm for ACTS mobile terminal
The initial advanced communication technology satellite (ACTS) mobile terminal (AMT) demonstrations will involve two-way communications between the high-bit-rate link evaluation terminal (HBR-LET), which is a fixed terminal (FT), and a van-housed mobile terminal (MT). The HBR-LET has the capability of adjusting its transmitted uplink power over an approximately 10-dB range to compensate for forward uplink rain attenuation. However, because of size and weight limitations, the MT cannot use power control as a rain compensation technique. Consequently, the AMT rain compensation algorithm (RCA) is based on a formula for varying the transmitted data rate in either direction to maintain link performance within acceptable limits. The objective of the AMT RCA is to ensure reliable operation in both the forward and return directions despite the possibility of uplink or downlink fading due to rain events in the vicinity of the FT or MT. In particular, the RCA must maintain at least a 3-dB link margin at the highest possible transmission rate (AMT can operate at 9.6, 4.8, or 2.4 kb/s) permitted by the prevailing channel conditions. The 3-dB minimum link margin is a system design safety factor to accommodate conceivable implementation losses.
Levitt, Barry K.↗