Issue 1 • Date Feb 1989
Repetition, diversity, and single-error-correcting codes are examined for use with binary modulation techniques over a mobile communication fading channel. Both bit-error performance and bandwidth efficiency are considered for phase-shift keyed, differential phase-shift keyed, and frequency-shift keyed modulations. The error-correction capability of repetition coding is considered, and optimum repetition is found.
M-tuple diversity with maximum-ratio-combining is then compared with repetition coding both with a single-error-correcting code and without coding. It is found that a minimum of a 10 dB signal-to-noise power ratio is required for an improved performance with repetition code or diversity. The repetition code is about 3 dB inferior to optimal diversity. An optimized design of moderate complexity and bandwidth expansion can be reached with twofold diversity and three repetitions as an inner layer of coding concatenated with an outer single-error-correcting code View full abstract»
The effects of time-delay spread on QAM with nonlinearity switched filters in a portable radio communications channelPage(s): 9 - 13
A spectrally efficient quadrature amplitude modulation (QAM) scheme with a simple nonlinearly switched filter is shown to provide a signaling waveform that is free from both intersymbol interference and zero-crossing timing jitter in a flat-fading channel. This modulation with coherent detection is evaluated by a computer simulation in a frequency-selective fading channel. Timing offset between in-phase and quadrature rails is varied. The effects of receiver filter bandwidths are also studied. It is found that this modulation is resistant to delay spread with moderate spectral efficiency and low complexity in a portable radio system, as compared to other spectrally efficient modulations View full abstract»
Probability of error analysis of digital partial response continuous phase modulation with noncoherent detection in mobile radio channelsPage(s): 19 - 30
An analysis is presented of noncoherent detection of constant-envelope digital partial-response continuous-phase modulation (PRCPM) in fast Rayleigh fading that characterizes land mobile radio channels. Closed-form expressions for the probability of error are derived for limiter discriminator detection, and both 1- and 2-bit differential detection. Numerical results are presented for cases of practical interest to researchers and designers of land mobile radio systems. The expressions derived for the probability of error are general and can be used for all PRCPM schemes View full abstract»
The stability of a slotted ALOHA system with capture effect is investigated under a general communication environment where terminals are divided into two groups (low-power and high-power) and the capture effect is modeled by capture probabilities. An approximate analysis is developed using catastrophe theory in which the effects of system and user parameters on the stability are characterized by the cusp catastrophe. In particular, the authors focus on the low-power group, since it must bear the strain under the capture effect. The stability conditions of the two groups are given explicitly by bifurcation sets View full abstract»
Various applications of surface-acoustic-wave (SAW) technologies are investigated in which the use of SAW devices would result in reduced volume and weight for VHF/UHF radio communication transceivers. Attention is given to improved insertion loss and power requirements reported for SAW filters. In particular, by analyzing the loss mechanisms of a previously developed high-performance SAW filter for mobile telephones, a new extremely low-loss SAW filter (loss of as low as 1.2-2.0 dB at 600 MHz) has been developed. The results of fundamental experiments for a SAW antenna duplexer using this new SAW filter as the transmitter filter with a semicoaxial filter as the receiver filter at 800 MHz are presented View full abstract»
Aims & Scope
IEEE Transactions on Vehicular Technology covers land, airborne, and maritime mobile services, vehicular electrotechnology, equipment, and systems identified with the automotive industry.
Meet Our Editors
Yuguang Michael Fang
University of Florida