Recent research has demonstrated that the capacity of a multipath-rich channel (such as indoors) is dramatically increased when antenna arrays are used at both transmitter and receiver. This is achieved by using the multipath to create parallel sub-channels. This ability to achieve parallelism in the channel is influenced by how much information about the channel is known at the transmitter, th...

In this paper, acquisition performance with adaptive pre-filtering is analyzed for a "coherent Paralperformance in a mobile fading channel. Under severe multiDath fading conditions. the P N code acauisition is difficult Y le1 matched-filter (MF) acquisition scheme with a reference filter (RF) in a multipath fading channel. Adaptive prefilterina is emoloved to reduce the effect of severe multipa...

In this paper, we present an improved channel matrix estimation algorithm for orthogonalfrequency-divisionmultiplexing downlink mobile communication systems using comb-type pilot. The channel matrix, which contains the channel frequency response and the coefficients of inter-sub-carrierinterference (ICI), is estimated using parametric multipath channel model. In the algorithm, we assume the del...

Successive interference cancellation is a promising technique for increasing the capacity of uplink CDMA channels. In this paper, the technique is extended to a low-earth orbit satellite channel. Unlike terrestrial cellular channels, satellite channels typically have a limited multipath profile, but significant closed-loop power control error due to the round-trip delay incurred in communicatin...

In this paper simulation results of DLR’s ultra-wideband land mobile satellite (LMS) multipath channel model are presented. The goal is the evaluation of GNSS performance in the rail environment. For this safety of life (SOL) application an urban railway was identified as the most critical scenario. The channel model is based on a measurement campaign of the land mobile multipath channel perfor...

High-speed communications over the underwater acoustic channel are difficult due to time-varying multipath propagation and Doppler scattering. These phenomena, however, can be effectively used for joint multipath-Doppler diversity of received signals similarly to multipath diversity in a conventional Rake receiver. We present a new signal processing technique for data transmission over fast fad...

In this paper, we propose a multiuser detection (MUD) scheme for space-time block coded orthogonal frequency division multiplexing (STBC-OFDM) systems. We derive the optimum weight matrix used to decouple simultaneously signals from active multiple access users using the minimum mean square error (MMSE) multiuser detection method. The proposed scheme provides good performance over different mod...

Low-density parity check (LDPC) codes of small, realizable size and regular form are analyzed in different multipath fading conditions. The multipath fading conditions vary from uncorrelated channels (with and without channel state information (CSI)) to a correlated land mobile channel at a frequency of 900 MHz. The effects of an external channel interleaver and varying mobile speed in a correl...

Abstract—This paper describes a non-blind technique, channel sounder, to characterize a wireless channel. This technique is based on the transmission of a pseudo random sequence through the channel, the calculation of its autocorrelation to estimate the channel impulse response, and from it the calculation of the Delay and Doppler spread parameters. This channel sounder was implemented using GN...