Henning Ehm

Diode power detector DC operating point in six-port communications receivers

In this paper a diode power detector circuit is investigated for application in a six-port communications receiver. The diode behavior is modeled by the fundamental diode equation, which is solved for the output DC operating point applying an expansion theorem of modified Bessel functions for the exponential function. The results are compared with a Harmonic Balance system simulation and the closely matching results show that the assumptions made to find the numerical solution hold true.

Six-port receiver local oscillator power selection for maximum output SNR

With an ideal model of a six-port communications receiver in mind, the optimal local oscillator (LO) power at the diode mixers for maximum signal-to-noise-ratio (SNR) at the baseband outputs is determined by simulations. The simulation setup contains the equivalent circuit for a diode mixer that has been used in a six-port communications receiver demonstrator [1]. By means of noise analysis and one tone harmonic balance simulations the SNR characteristics with respect to the LO power is derived in the presence of diode shot noise, and of diode shot noise combined with LO phase noise. The results show that a properly adjusted LO power is essential for the receiver performance.

Analytic quantization modeling of OFDM signals using normal Gaussian distribution

This paper presents a rigorous analytic approach for the quantization of OFDM signals. The signal-to-noise ratio at the ADC output is derived as a function of the input signals standard deviation and the ADC input range. Furthermore, the maximum signal-to-noise ratio is calculated for various ADC resolutions. The analytic results are verified by simulations applying an OFDM WLAN signal as well as normal distributed white Gaussian noise.

Investigation of DC-Offset and flicker noise for combined single shot Galileo/GPS receivers with homodyne front-end architecture

This paper presents quantitative theoretical and simulative results on the sensitivity of a combined single shot Galileo/GPS receiver with homodyne front-end architecture due to DC-offset, flicker noise, and resolution of the analog to digital converter.

Analysis of System Parameters of a Six-Port Communications Receiver with Analog I/Q Regeneration

In this paper system level parameters for the compression behavior as well as second and third order distortions of a six-port communications receiver with analog I/Q regeneration are determined by system simulations. The parameter values are qualified for a range of local oscillator (LO) signal powers. A recommendation for a well-suited LO signal power is derived from the resulting parameter plot. The recommended LO signal power is supported by investigation of the receivers conversion efficiency. The results are also valid for other ways of I/Q regeneration based on passive mixing.

A Novel Technique for Determining Kernels of Volterra Based Behavioral Models for RF Amplifiers

This paper presents a new technique to determine the kernels of Volterra series based behavioral models of RF amplifiers in the frequency domain. A model with three kernels and a memory length of one is developed. The kernels of this model are assigned only by using a two-tone test. No knowledge of the integrated circuit is needed to determine all model parameters. The derivation of such a model out of well known mathematical basics is shown such as the used measurement setup. Measured data and simulation deliverables are being compared and show a good match. A comparison between a Saleh model and the new modeling approach concludes this paper.

Analysis of Combined Frequency Drift and Offset for Galileo/GPS Single Shot Receiver Architectures

This paper analyzes the combined effect of a residual frequency offset and drift after down-conversion for single shot receiver architectures as they are currently utilized in mobile terminals for GPS reception. The change in the receiver detection probability due to this effect is calculated, as well as the associated connected sensitivity-loss. The obtained results are given for the GPS C/A code and open Galileo signal, both in the L1 band.