Pilot-Symbol-Aided 16PSK and 16QAM for Digital Land Mobile Radio Systems

The paper proposes a novel pilot-symbol-aided (PSA) technique for fading compensation of digital signals in the mobile environments. In a PSA system, the data sequence at the transmitter is divided into frames of data. A pilot symbol from a known pseudoradom-symbol sequence is inserted periodically into a frame of data symbol for transmission. In a conventional PSA-receiver, these pilot symbols are extracted from the received signal and used to estimate the effects of signal distortion introduced in the fading channel. The resultant estimates are then used to correct the distortion effects in the received data frames. In the paper, a novel estimation technique that uses the data symbols as well as the pilot symbols is proposed. The technique has the major advantages of simple implementation and short storage-delay time. Results are presented in a series of computer-simulation tests. These assess the effectiveness of the estimation technique on the BER performances of a 16-ary phase-shift keyed (16PSK) and a 16-ary quadrature-amplitude modulated (16QAM) signals in the frequency-selective and frequency-nonselective Rayleigh fading channels. The channels are corrupted by co-channel interference or additive white Gaussian noise. Results of differential-detected 16PSK and star-16QAM signals are also presented for comparison. It has been shown that, the use of PSA technique can significantly improve the bit-error-rate performances of the systems, relative to those using differential detection.postprin

Performance of a pilot symbol-aided technique in frequency-selective Rayleigh fading channels corrupted by co-channel interference and Gaussian noise

The paper studies the effects of a pilot symbol-aided (PSA) technique on the performances of 16QAM and 16PSK in the frequency-selective Rayleigh fading channels corrupted by co-channel interference and Gaussian noise. The PSA technique employs both the pilot symbols and data symbols for fading estimation. Computer simulation results have shown that significant improvements on bit-error rate performances of the signals can be achieved through the use of the PSA technique.published_or_final_versio

A Faded-Compensation Technique for Digital Land Mobile Satellite Systems

This paper proposes a novel fade-compensation algorithm using a pilot symbol-aided technique for digital and mobile satellite systems. In a conventional pilot symbol-aided system, a pilot symbol from a known pseudorandom-symbol sequence is inserted periodically into the data-symbol sequence in the transmitter. At the receiver, these pilot symbols are extracted from the received signal and used to estimate the signal distortion introduced in the fading channel. The resultant estimate is then used to correct the fading effects in the received data symbols. In this paper, a novel fade-compensation technique that uses both the pilot symbols and the data symbols is proposed. A series of computer-simulation tests has been carried out to assess the effectiveness of the technique on the bit-error-rate (BER) performances of an uncoded 16-ary phase-shift keyed (16PSK) and an uncoded 16-ary quadrature-amplitude modulated (16QAM) signal over the land mobile satellite channels. The results have shown that substantial improvements in the BER performances of the systems can be obtained, compared to those using only the pilot symbolspostprin

Performance of a Faded-Compensated 16QAM with Diversity Reception in Mobile radio Channels

The paper studies the bit-error-rate (BER) performance of a fade-compensated 16 QAM with two-branch postdetection selection combining diversity reception in the Rayleigh fading channels. A pilot symbol-aided (PSA) technique that uses both pilot symbols and data symbols is employed for fading compensation. Computer simulation results have shown that, the use of diversity reception technique can significantly improve the BER performance when the normalized delay between the signals at the two receivers is small. It is also shown that, the error-floor is sensitive to the normalized delay, but relatively less sensitive to the power ratio between the signals at the two receivers.published_or_final_versio

Performances of 16QAM with fading compensation and postdetection diversity reception in satellite mobile channels

This paper studies the effects of N-branch postdetection selection diversity reception, where N = 1, 2, 3 or 4, incorporated with fading compensation on a digital satellite mobile system. The digital satellite mobile system transmits a pilot-symbol-aided 16-ary quadrature-amplitude modulated (PSA-16QAM) signal over the Rician channels. A selection method that makes use of the pilot symbols to select one of the N branches in the diversity reception system for signal detection, and a novel PSA technique that makes use of both the pilot symbols and data symbols for fading compensation, are proposed. Computer simulation tests are used to assess the effects of the proposed techniques on bit-error rate performances (BER) of the PSA-16QAM system in the presence of additive white Gaussian noise (AWGN) or co-channel interference (CCI) in the Rician faded channels. When frequency diversity is used, PSA-16QAM with 2-branch and 4-branch diversity reception occupies about the same bandwidths as quaternary phase-shift-keying (QPSK) without using diversity and with 2-branch diversity, respectively, yet achieving the same capacity. Thus, simulation tests on the BER performances of a QPSK system without diversity and with 2-branch diversity are also carried out and the results are used to determine the preferred system arrangements. ©1997 John Wiley & Sons, Ltd.postprin

Multipath fading compensation technique using pilot and data bearing symbols in mobile radio channels

Conference Theme: The Global BridgeThe paper studies techniques for transmitting a 16-ary quadrature-amplitude modulated (16QAM) signal in different mobile radio environments. Conventional multipath fading compensation techniques using only the pilot symbols, incorporated with zeroth-order and first-order prediction methods, are studied. Novel techniques making use both the pilot symbols and the data symbols, together with the improved zeroth-order and first-order prediction methods, are proposed. A series of intensive Monte Carlo simulations has been carried out on these techniques and the results have shown that, at high signal-to-noise ratios (SNRs), the bit-error rate (BER) performance can be reduced by a factor of about 46 and 2 using the improved zeroth-order and first-order prediction respectively, relative to those obtained using the pilot symbols only.published_or_final_versionThe 1994 IEEE Global Telecommunications Conference (GLOBECOM '94), San Francisco, CA., 28 November-2 December 1994. In Globecom. IEEE Conference and Exhibition, 1994, v. 2, p. 1009-101

A robust global motion estimation scheme for sprite coding

2002-2003 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Improved pilot symbol-aided transmission technique for hybrid satellite and terrestrial mobile systems

In the hybrid satellite and terrestrial mobile systems, robust transmission techniques are required to compensate the signal distortion introduced in the fading channels. Recently, the pilot symbol-aided techniques have been proved to be suitable for the transmission of digital signals over satellite mobile and terrestrial mobile channels. In this paper, an improved pilot symbol-aided transmission technique suitable for the hybrid systems is proposed. The proposed technique uses the distortion information in data symbols as well as in pilot symbols for the multipath fading compensation. Monte Carlo simulations have been carried out to investigate the effects of the proposed technique on the bit-error rate (BER) performances of 16PSK and 16QAM signals in satellite mobile and terrestrial mobile channels. Results have shown that, at high signal-to-noise ratios (SNRs), an improvement of more than two orders of magnitude in the BER performance can be obtained by the proposed technique, relative to those only using the pilot symbols.published_or_final_versio

Utilization of glucose, blood pressure, and lipid lowering medications among people with type II diabetes in the United States, 1999-2010

postprin