Eun Su Kang

Channel estimation with pilot signal design for terrestrial UDTV using MISO technology

A time-domain channel estimation algorithm is proposed for ultrahigh-definition television (UDTV) with multi-input single-output (MISO) systems. The proposed algorithm can estimate a long channel exactly by arranging the impulsive signals in the time-domain through the pilot design in the frequency-domain.

A Fast Suboptimal Algorithm for Detection of 16-QAM Signaling in MIMO Channels

We develop a computationally efficient approximation of the maximum likelihood (ML) detector for 16 quadrature amplitude modulation (16-QAM) in multiple-input multiple-output (MIMO) systems. The detector is based on solving a convex relaxation of the ML problem by an affine-scaling cyclic Barzila-Borwein method for box constrained optimization. Simulation results in a random MIMO system show that this proposed approach outperforms the conventional decorrelator detector and is similar to the semidefinite relaxation (SDR) detector. However, we should note that the complexity of the proposed approach is less than that of those detectors. In the case of 8 antennas and 4 users, about 99% fewer computations are required than the SDR and ML detectors.

Improved speed near field communication with rotated QPSK constellation and hidden data transmission

A quadrature phase shift keying (QPSK) modulation with additional data transmission is proposed to improve throughput for near field communications. The additional data is transmitted by the phase rotation of the constellation.

Channel Estimation for MIMO System by using Orthogonal Code with Comb Type Pilot

In this paper, we propose the channel estimation for the space time coded-orthogonal frequency division multiplexing (ST-OFDM) muti-input multi-output (MIMO) system with comb type pilot arrangements. In the conventional method, specially constructed pilots are inserted in the OFDM symbols at all transmit antennas separately. The proposed algorithm multiplies the orthogonal code to be transmitted OFDM symbols to estimate channels at the receiver. This algorithm can estimate a long channel delay with high accuracy. It is proved by computer simulations.

Improving equalization performance with noise reduction for DVB-T/H

An equalization algorithm is proposed for DVB-T/H systems to reduce noise effect by averaging equalized results with different signal intervals for the same OFDM symbol. It has a signal-to-noise gain of 0.5 dB over conventional algorithm.

Channel Estimation with Orthogonal Code in MIMO System

In this paper, we improve a time-domain channel estimation algorithm with multi-input multi-output (MIMO) systems for the next-generation digital television (DTV). The conventional algorithm use orthogonal codes for separating channels from the time-domain orthogonal frequency division multiplexing (OFDM) symbols. However. it has the disadvantage of reduced data-rate because of many pilots. The improved algorithm shows better performance than the conventional one even with reduced number of pilots. The improved algorithm is evaluated by computer simulations.

Erratum to "A fine carrier recovery algorithm robust to doppler shift for OFDM systems" [Aug 10 1218-1222]

In this paper, a fine carrier recovery algorithm is proposed to maintain a good performance even with Doppler shifts for OFDM systems. It estimates the frequency offset by utilizing two correlation values for intentionally added positive and negative frequency offsets. Its performance is compared with conventional algorithms such as Beek and Moose algorithms.

Turbo decoder for second generation digital video broadcasting system

A turbo decoder is proposed for the next generation DVB-T system. The proposed decoder iteratively exchanges information between the maximum a posteriori (MAP) soft-input soft-output (SISO) detector and SISO low density parity check (LDPC) channel decoder.

Bidirectional DFE Arbitrated by Viterbi Decoder Path Metrics

A bidirectional decision feedback equalizer (DFE) is proposed with the arbitration of the Viterbi decoder. The proposed DFE uses the minimum path metric between Viterbi decoders for the forward and reverse DFEs in the arbitration process. It has over 2 dB SNR gain against the conventional bidirectional DFE and the single DFE.