A novel multipath diversity scheme used in TDD-CDMA systems is presented. A FIR filter is added in the transmitter, while a RAKE combiner is used in the receiver. The optimum FIR filter problem may be viewed as an eigenvalue problem. The multiple antennas system is also analyzed. Results show that this new scheme can greatly improve the output Signal to Noise Ratio (SNR) compared with conventio...

For high data rate ultra wideband communication system, performance comparison of Rake, MMSE and Rake-MMSE receivers is attempted in this paper. Further a detail study on Rake-MMSE time domain equalizers is carried out taking into account all the important parameters such as the effect of the number of Rake fingers and equalizer taps on the error rate performance. This receiver combats inter-sy...

We have considered multiuser communication scenario with ultra wideband (UWB) communication. UWB device is transmitting the data by time hopping (TH)-based system, TH-PPM, TH-PAM and DS-UWB. The UWB device is transmitting data over multipath rich channel model recommended by IEEE 802.15.3a working group. This channel model is based on Saleh-Valenzuela model. For better performance at receiver s...

The Rake receiver is a well known technique in spread spectrum systems, which is used to obtain signal diversity in multipath environments. In TDD systems, a technique known as pre-Rake has been proposed recently, in which the signal-processing is transferred to the transmitter, and it has been shown that this technique provides a capacity increase in the downlink. In this paper we propose a co...

The performance of a RAKE receiver for a pulse based ultra-wideband (UWB) communications system is studied in a realistic channel model that is based on an extensive set of indoor channel measurements. The RAKE receiver is shown to contribute to a mitigation of the ISI. In particular, at low input SNR values and small number of RAKE taps, it is shown that employing additional RAKE taps for ener...

Recently, ultra wideband (UWB) technology has been proposed for use in wireless personal area networks (WPANs). Under the conditions where such transceivers are expected to operate, intersymbol interference (ISI) will become a significant performance limitation, and improvements to conventional RAKE reception will be necessary. We propose a modified RAKE receiver that finds an optimal balance b...

In this paper, a space-time RAKE (ST-RAKE) receiver with enhanced interference rejection is proposed for CDMA communications systems over a multipath fading channel. The proposed scheme involves three stages. An interference-blocking (IB) transformation is first developed based on the received data (undespread data) for suppressing the strong interference. Optimum beamforming is then performed ...

in this study, the performance of a fabricated fluffer was evaluated and compared with common field curing methods for alfalfa. the drying rate, baling loss and alfalfa nutrient value (dry matter and crude protein) were the criteria for evaluation. the alfalfa was cut using a mower-conditioner. a randomized complete block experimental design was used with three treatments (fluffing swathed alfa...