Jinyoung An

An improved UWB receiver employing generalized normal-Laplacian distribution model

The generalized normal-Laplace (GNL) distribution is employed to reflect the heavy-tailed and impulsive nature of the multiple access interference (MAI) plus AWGN noise in ultra-wideband (UWB) systems. To accurately represent the impulsive feature of the MAI-plus-noise while keeping longer tails, the kurtosis matching (KM) method combined with the method of moments estimation (MME) is proposed for the parameter estimation for time-hopping UWB multiple access communications in AWGN channels. The GNL based UWB receiver using the KM approach outperforms the conventional matched filter receiver, the soft-limiting receiver, the Gaussian-Laplace mixture receiver, and the MME-based GNL receiver in high SNR ranges.

Performance of spatial multiplexing MIMO receivers in frequency selective rayleigh fading channels

In this paper, the error performance of various spatial multiplexing (SM) schemes on frequency selective Rayleigh fading channels is investigated. The work presented here considers several multiple-input multiple-output (MIMO) detection approaches such as zero forcing (ZF), minimum mean square error (MMSE), successive interference cancellation (SIC) and sorted QR decomposition (SQRD) in order to cope with inter-channel interference for the MIMO detection scheme followed by RAKE maximal ratio combining (MRC). The error performance and computational complexity of several detection algorithms are comparatively studied via simulations.

Spatial Multiplexing Receivers in UWB MIMO Systems based on Prerake Combining

In this paper, various ultra-wideband (UWB) spatial multiplxing (SM) multiple input multiple output (MIMO) receivers based on a prerake diversity combining scheme are discussed and their performance is analyzed. Several UWB MIMO detection approaches such as zero forcing (ZF), minimum mean square error (MMSE), ordered successive interference cancellation (OSIC), sorted QR decomposition (SQRD), and maximum likelihood (ML) are considered in order to cope with inter-channel interference. The UWB SM systems based on transmitter-side multipath preprocessing and receiver-side MIMO detection can either boost the transmission data rate or offer significant diversity gain and improved BER performance. The error performance and complexity of linear and nonlinear detection algorithms are comparatively studied on a lognormal multipath fading channel.

Performance of UWB MIMO Systems with Rake Receive Processing

In this paper, a rake diversity combining scheme for detection of a single data stream in ultra-wideband (UWB) multiple input multiple output (MIMO) systems is considered as an extension of single input multiple output (SIMO) systems. The BER performance of a linear receive rake diversity scheme is presented in a log-normal multipath fading channel. It is shown that the increase of an antenna dimension happens to degrade the performance in the range of high SNRs. It is seen that as the number of transmit and receive antennas increases, the rake diversity combining system improves the performance at low SNRs or in the case of large antenna dimension at high SNRs.

Error performance analysis of 2PPM-TH-UWB systems with spatial diversity in multipath channels

In this paper, we investigate the performance improvement of binary pulse position modulation (2PPM) time hopping (TH) ultra-wideband (UWB) systems employing multiple receive antennas to achieve high data rate communications in multipath channel scenarios. The effects of spatial and temporal diversities are analyzed on the performance of 2PPM-TH-UWB systems. The diversity performance is evaluated for different numbers of antenna elements and selected multipaths. The tradeoff between the antenna array size and the number of Rake fingers is also compared.

Beamformer-based Acquisition in MIMO-CDMA Communication Systems

This paper proposes the code acquisition scheme on a MIMO channel for preamble search in a MIMO-CDMA uplink system. The performance of a ML code acquisition technique based on transmit and receive beamforming is analyzed by considering the detection probability. The acquisition performance and MAT for a MIMO code acquisition system are numerically evaluated. It is shown that the multiple transmit antennas can give the code acquisition system a transmit beamforming gain and result in much better performance than the corresponding scheme with a SIMO case.

Error Performance Analysis of Multi-User Binary PAM TH UWB Systems with Multiple Receive Antennas

In this paper, multiple receive antennas are applied to multi-user binary pulse amplitude modulation (2PAM) time hopping (TH) ultra-wideband (UWB) systems to achieve high-data-rate communications. The effects of spatial diversity on the performance of 2PAM-TH-UWB systems are analytically investigated. We derive the expression for the received SINR after spatially combining and evaluate the bit error rate (BER) performance. Numerical results show that the BER performance can be enhanced by spatial diversity combining.