Seung-Geun Kim

Transition probabilities of coded BPSK signals for hard-decision decoding with k-bit CSI in Nakagami-m fading channels

We evaluate a closed form expression of the transition probabilities used for calculating metric values and pairwise error probabilities of convolutional codes, equipped with coherent BPSK signals, for hard-decision decoding with k-bit channel state information (CSI) in slow varying frequency nonselective Nakagami-m fading channels. It is noted that 1-bit CSI is sufficient to take advantage of channel information under deep fadings.

Performance analysis of MTCM/CPFSK in correlated Rayleigh fading channels with perfect channel information

The upper bound on the pairwise error probability of MTCM/CPFSK with coherent detection is derived using a linear transformation for orthogonalizing the autocorrelation matrix of Rayleigh fading process with perfect CSI in the presence of an additive white Gaussian noise and a correlated Rayleigh fading. The analyzed performance well estimates the simulated performance for Doppler frequencies when BER is lower than 10/sup -3/.

A digital sinusoid synthesis based on the postscaled CORDIC

The CORDIC algorithm can be implemented efficiently for digital synthesis of a sinusoidal waveform which is important in modern digital communication field. Since CORDIC rotation is not pure rotation but an expanded rotation, a normalization operation is required to get exact sinusoidal waveforms. In this paper, we implement the postscaled CORDIC sinusoidal generator and compare the performances of two CORDIC-based sinusoidal generators with prescaling scheme and post-scaling scheme. As a result of comparison, the error performance of the postscaled generator is better than that of prescaled generator. Specifically, to get 3 precision bits in the sine function generation, the mean error performance of the postscaled CORDIC digital sinusoidal generator is increased by about 35.24% compared with the prescaled CORDIC digital sinusoidal generator.

Performance of OFDM with postdetection-combining-based macrodiversity on a shadowed multipath channel

Performance of OFDM using postdetection-combining-based macrodiversity is analyzed on a shadowed multipath channel, and the effect of correlated shadowing is investigated. We show that the postdetection-combining-based macrodiversity gives larger performance gain than its selection-based counterpart, and yields much better performance than no diversity case even for the fully correlated shadowing situation.

Implementation of 40 Mbps burst QPSK receiver with NDA timing and frequency synchronization

This paper presents a case of design and implementation of a high-speed burst QPSK (quaternary phase shift keying) receiver. Since the PSK modulation transmits its information within the phase, the baseband digital receiver can recover the transmitted symbol from the received phase. Symbol time and frequency offset estimators estimate symbol time and frequency offset using sample data over 32 symbols without transmitted symbol information, respectively, and internal RAM is used for the received phase delay over the estimation time. The receiver is implemented using about 92000 gates of Samsung KG75 SOG library, which uses 0.65 /spl mu/m CMOS technology. The chip test result shows that the receiver operates at 40 MHz clock rate on 5.6 V, which is equivalent to the 40 Mbps data rate.