Ji-Woong Choi

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—The performance of channel estimation in orthogonal frequency division multiplexing (OFDM) systems significantly depends on the pilot signal, which is usually scattered in time and frequency domains. For a given pilot density, the authors optimally design the pilot pattern so as to minimize the mean squared error (MSE) of the channel estimate with the use(More)
—The efficient service of a tremendous number of machine-type devices with heterogeneous traffic types may consider simple random access as a solution. For more rigorous analysis of system performance in multicell environments, it is required to consider not only the packet collisions within the same cell but also the interference from other cells. This(More)
– In order to achieve the goals of business, various channel of communications to customers have to be developed through technology. In the present day banking, total automation of banking operation and is an imperative for all banks to attract more customers, provide efficient service and survive the competition ,apart from achieving the profit ,which is(More)
The performance of channel estimation in OFDM systems significantly depends on the pilot signal, which is usually scattered in the time and frequency domains. For a given pilot density, we analytically design the optimum pilot pattern that minimizes the mean square error of the channel estimate obtained with the use of general interpolators. The analytic(More)
—When a preamble signal is repeated multiple times in OFDM systems, we derive joint maximum likelihood (ML) estimation of the frame timing (FT) and carrier frequency offset (CFO). Unlike conventional estimators which use correlation of adjacent repetition patterns only or some specific sets of patterns, the joint ML estimation exploits correlation of any(More)
SUMMARY The performance of a MIMO-OFDM system significantly depends upon the accuracy of the channel impulse response (CIR) estimates. In the presence of correlation between the CIRs of the transmit or receive antennas, it is desirable to exploit this correlation to improve the performance of CIR estimation. In this letter, we propose a low-complexity(More)