Y. Krikorian

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The performance of multicarrier frequency division multiple access (FDMA) wireless communication systems is impacted by amplifier nonlinearities. It is vital to precisely model limiters and high power amplifiers (HPAs) to determine the spectrum distortion and other types of degradation associated with multicarrier communication systems. Contemporary(More)
Amplifier nonlinearities impact the performance of multicarrier frequency division multiple access (FDMA) wireless communication systems. It is important to accurately model limiters and high power amplifiers to predict the bit error rate performance of multicarrier communication systems. Modern simulation tools can be used to accurately determine(More)
Telemetry, tracking, and command are very important functions necessary for the proper operation of a satellite. It becomes a critical issue for the LEO-Sat program, however, when the command and control is provided from a small ground station with limited capabilities (low transmit EIRP and receive G/T), and when the satellite is in a contingency mode of(More)
The USB/STDN waveform (unified S-band/spaceflight tracking and data network) has been used to provide telemetry, tracking, and command (TT&C) services for many satellites in addition to NASA near-earth orbital missions. The tracking and command signals are used in the forward link, or the uplink (earth-to-space), while the spacecraft tracking and(More)
In modern satellite systems the uplink RF wideband signal after downconversion to IF is input to an ADC, which is a major limitation as it needs to operate at a rate at least 2/spl times/ the received signal bandwidth. In the case of a wideband signal comprised of many multiplexed signals, the spectral distribution of quantization noise is also of(More)
The Jupiter icy moons orbiter (JIMO) high capability instrument (HCI) concept study examined a hypothetical suite of remote-sensing instruments that could take advantage of the large amounts of power available from a space nuclear reactor, and provide orders of magnitude of improvement in resolution and data return. A team of engineers at The Aerospace(More)
This paper presents analytical and detailed computer simulation results of the performance enhancement of pulse code modulation/frequency modulation (PCM/FM) links using Reed Solomon (RS) channel coding. PCM/FM is a commonly deployed technique for a wide variety of telemetry and other links. Nevertheless, the required SNR to provide acceptable bit error(More)
A dynamic deep space communication link analysis tool is described in this paper. This tool, developed by The Aerospace Corporation, provides the capability to analyze coverage and data throughput for communication links between a spacecraft and the Jet Propulsion Laboratory's (JPL) Deep Space Network (DSN). The tool determines the link margin and data(More)
A model is described in this paper for dynamic S-band telemetry link analysis for the spacelift range system (SLRS). From an operational standpoint, this tool determines telemetry link closure of a launch vehicle to different ground terminal sites. This model allows the users to react accordingly to any anomalies and to perform subsequent corrective(More)
The performance of band limited M-ary PSK communication systems is impacted by amplifier nonlinearities. It is critical to precisely model high-power amplifiers (HPAs) to ascertain the bit error rate (BER) performance of M-ary PSK communication systems, which are band limited. State-of-the-art simulation techniques can be employed to exactly ascertain(More)