Pilot-symbol Assisted Carrier Synchronization: Cramer-rao Bound and Synchronizer Performance
نویسندگان
چکیده
This contribution considers the joint estimation of the carrier phase and the frequency offset from a noisy linearly modulated burst signal containing random data symbols (DS) as well as known pilot symbols (PS). The corresponding Cramer-Rao lower bound (CRB) is derived. This bound indicates that it is potentially more accurate to estimate carrier phase and frequency from such a ‘hybrid’ burst than from a burst without PS or from the limited number of PS only. The new bound is compared with the performance of new and existing carrier synchronizers. We present the iterative soft-Decision-Directed (sDD) estimator with combined data-aided/non-data-aided (DA/NDA) initialization, which performs closely to the CRB, and provides a large improvement over the classical NDA estimator at low and moderate signal-to-noise ratio (SNR).
منابع مشابه
Timing Synchronization with Turbo Codes on AWGN Chan- nels
This paper presents the behaviour of a turbo coding scheme when the symbol timing is not perfectly known. The algorithm for timing synchronization together with the theoretical Cramer Rao bound and the performance of an NDA ML synchronizer are presented. It is shown that synchronization can be achieved using the soft bit outputs of the turbo decoder without the need of using complex separate sy...
متن کاملSynchronization at low SNR: performance bounds and algorithms
This contribution compares several types of feed-forward synchronization algorithms when applied to powerful error-correcting codes. As such codes operate at very low SNR, conventional synchronization algorithms often prove to be unreliable. By exploiting the code properties we may improve the synchronization performance. We investigate a code-aided synchronizer that operates according the EM a...
متن کاملCarrier Phase Recovery in Turbo Receivers: Cramer-Rao Bound and Synchronizer Performance
This contribution considers carrier phase recovery in turbo receivers. We point out that the resulting Cramer-Rao bound (CRB) is close to its high signal-to-noise ratio (SNR) asymptote, even at the typical low operating SNR of turbo systems. We show that ‘code-unaware’ phase estimators are unable to perform closely to the CRB at the normal operating SNR of powerful codes. The advantage of ‘code...
متن کاملA Novel Frequency Synchronization Algorithm and its Cramer Rao Bound in Practical UWB Environment for MB-OFDM Systems
This paper presents an efficient time-domain coarse frequency offset (FO) synchronizer (TCFS) for multi-band orthogonal frequency division multiplexing (MB-OFDM) systems effective for practical ultra-wideband (UWB) environment. The proposed algorithm derives its estimates based on phase differences in the received subcarrier signals of several successive OFDM symbols in the preamble. We conside...
متن کاملML-oriented NDA carrier synchronization for general rotationally symmetric signal constellations
In this contribution we point out that the nondecision-aided (NDA) carrier synchronizer, maximizing the low E s / N o limit of the likelihood function averaged over a general 2r/N-rotationally symmetric signal constellation, reduces to the familiar timing-aided Nth power synchronizer; this extends a result from [6] where only M-PSK constellations have been considered. Whereas in the case of M-P...
متن کامل