Hyoung-Kyu Song

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This letter evaluates the peak-to-average power ratio (PAR) performance in a space-time block coded (STBC) multi-input multi-output orthogonal frequency-division multiplexing (MIMO-OFDM) system using the selective mapping (SLM) approach. The investigated SLM-based MIMO-OFDM system selects the transmitted sequence with the lowest average PAR over all(More)
A combining of MIMO signal processing with OFDM is regarded as a promising solution of enhancing the performance of next generation wireless system. Therefore, in this paper, an OFDM-based wireless system employing layered space-time architecture is considered for a high-rate transmission. With an emphasis on a preamble design for multi-channel separation,(More)
This letter is concerned with a frequency-offset estimation technique for OFDM-based transmission systems. The frequency estimation technique utilizes a repetitive signal structure inside of a OFDM symbol which is used to enlarge the range and increase the accuracy of offset estimation. Also, an averaged decision-directed channel estimation (ADDCE)(More)
We analyze the bit-error rate (BER) performance of the distributed Alamouti’s code for cooperative diversity networks consisting of a source, two relays and a destination node over Rayleigh fading channels. It is assumed that the relays adopt the amplify-and-forward protocol. Firstly, assuming the existence of the direct path component from the source to(More)
For the decode-and-forward protocol in relay networks, opportunistic relaying (OR) and selection cooperation (SC) are two major relay selection schemes, which have been studied only for single antenna terminals. We study OR and SC in a multi-antenna relay network where each terminal has multiple antennas. To fully exploit multiple antennas without incurring(More)
This paper focuses on average bit error rate (BER) and diversity order analysis of distributed Alamouti's code in dissimilar cooperative networks with channel state information (CSI)-assisted relays. We first assume that the relays adopt the amplifying coefficient proposed in [1]. A lower and an upper bounds of the average BER of the distributed Alamouti's(More)