Carrier-phase synchronization can be approached in a
general manner by estimating the multiplicative distortion (MD) to which
a baseband received signal in an RF or coherent optical transmission
system is subjected. This paper presents a unified modeling and
estimation of the MD in finite-alphabet digital communication systems. A
simple form of MD is the camer phase exp GO) which has to be estimated
and compensated for in a coherent receiver. A more general case with
fading must, however, allow for Amplitude as well as phase variations of
the MD.
We assume a state-variable model for the MD and generally obtain a
nonlinear estimation problem with additional randomly-varying system
parameters such as received signal power, frequency offset, and Doppler
spread. An extended Kalman filter is then applied as a near-optimal
solution to the adaptive MD and channel parameter estimation problem.
Examples are given to show the use and some advantages of this scheme.
In this letter, the error performance of an ultra-wideband (UWB) system with a hybrid pulse Amplitude and position modulation (PAPM) scheme over indoor lognormal fading channels is analyzed. In the PAPM UWB system, input data is modulated onto both the pulse Amplitudes and pulse positions.
The following is a list of MATLAB codes which includes the radar
absorbing material design, the antenna pattern, the observation points generation, and the Amplitude
error and phase error calculations.
The Hilbert Transform is an important component in communication systems, e.g. for single sideband modulation/demodulation, Amplitude and phase detection, etc. It can be formulated as filtering operation which makes it possible to approximate the Hilbert Transform with a digital filter. Due to the non-causal and infinite impulse response of that filter, it is not that easy to get a good approximation with low hardware resource usage. Therefore, different filters with different complexities have been implemented.
The detailed discussion can be found in "Digital Hilbert Transformers or FPGA-based Phase-Locked Loops" (http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4629940).
The design is fully pipelined for maximum throughput.
Nature is seldom kind. One of the most appealing uses for radio-
telephone systems—communication with people on the move—must over-
come radio transmission problems so difficult they challenge the imagina-
tion. A microwave radio signal transmitted between a fixed base station
and a moving vehicle in a typical urban environment exhibits extreme
variations in both Amplitude and apparent frequency.
