Mobile operators must continuously pursue cost‐
effective and efficient solutions to meet the high data
demand requirements of their subscribers. Limited spectrum
allocations and non‐contiguous spectrum blocks continue
to pose challenges for mobile operators supporting large
data uploads and downloads across their networks. With the
increase in video and social media content, the challenges
have increased exponentially.
LTE-Advanced becomes a truly global standard for 4G cellular communications.
Relay, as one of the key technologies of LTE-Advanced, can significantly extend
the coverage, and improve the system throughput. LTE-A standards and tech-
nologies were described in several recent books where the limited pages for relay
feature prevent the detailed explanations of the technology. In this book, we tried
to provide an in-depth description of LTE-A relay development. More specifically,
significant portions are spent on relay channel modeling and potential technologies
during the study item phase of the development, although some of those tech-
nologies, such as Type 2 cooperative relay, multi-hop relay, relay with backhaul of
carrier aggregation, were not standardized in Release 10 LTE.
We address the problem of blind carrier frequency-offset (CFO) estimation in quadrature amplitude modulation,
phase-shift keying, and pulse amplitude modulation
communications systems.We study the performance of a standard
CFO estimate, which consists of first raising the received signal to
the Mth power, where M is an integer depending on the type and
size of the symbol constellation, and then applying the nonlinear
least squares (NLLS) estimation approach. At low signal-to noise
ratio (SNR), the NLLS method fails to provide an accurate CFO
estimate because of the presence of outliers. In this letter, we derive
an approximate closed-form expression for the outlier probability.
This enables us to predict the mean-square error (MSE) on CFO
estimation for all SNR values. For a given SNR, the new results
also give insight into the minimum number of samples required in
the CFO estimation procedure, in order to ensure that the MSE
on estimation is not significantly affected by the outliers.
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.
This paper investigates the design of joint frequency
offset and carrier phase estimation of a multi-frequency time division
multiple access (MF-TDMA) demodulator that is applied to
a digital video broadcasting—return channel system via satellite
(DVB-RCS). The proposed joint estimation algorithm is based on
the interpolation technique for two correlation values in the frequency
and phase domains. This simple interpolation technique
can significantly improve frequency and phase resolution capabilities
of the proposed technique without increasing the number of
the correlation values. In addition, the overall block diagram of a
digital communications receiver for DVB-RCS is presented, which
was designed using the proposed estimation algorithms.
Index Terms—Carrier phase estimation, DVB-RCS, frequency
offset estimation, interpolation, joint estimation, MF-TDMA.
demodulates the FM modulated signal Y at the carrier frequency Fc (Hz). Y and Fc have sample frequency Fs (Hz).
FREQDEV is the frequency deviation (Hz) of the modulated signal.
uses the message signal X to modulate the carrier frequency Fc (Hz) and sample frequency Fs (Hz), where Fs >
2*Fc. FREQDEV (Hz) is the frequency deviation of the modulated signal.
