Reduction of the power consumption in portable wireless receivers is an important consideration for next-generation cellular systems specified by standards such as the UMTS, IMT2000. This paper explores the architectural design-space and methodologies for reducing the dynamic power dissipation in the Direct Sequence Code Division Multiple Access (DS-CDMA) downlink RAKE receiver. Starting with a...

Ultra-wideband (UWB) communication systems occupy huge bandwidths with very low power spectral densities. This feature makes the UWB channels highly rich in resolvable multipaths. To exploit the temporal diversity, the receiver is commonly implemented through a Rake. The aim to capture enough signal energy to maintain an acceptable output signal-to-noise ratio (SNR) dictates a very complicated ...

UWB shows great promise for use in a number of wireless communications applications, in particular, short range high bit rate networking. However, due to the emissions limits set by the FCC, commercial systems are limited in range for high data rates. To achieve greater range, both simple and advanced techniques need to be investigated. Current designs for UWB (at least those in the open litera...

We address the problem of multiuser detection in fast fading multipath environments for DS-CDMA systems. In fast fading scenarios, temporal variations of the channel cause significant performance degradation even with the RAKE receiver. We use a previously introduced Time-Frequency (TF) RAKE receiver based on a canonical formulation of the channel and signals to simultaneously combat fading and...

Acceleration of semiconductor technologies has enabled incorporation of GPS receivers in small inexpensive hand held battery operated devices. As the size of chipsets for different communication protocols diminishes in size, building multi-protocol communication systems including GPS receivers has become not only attractive but also possible. A limitation of current approaches requires the Base...

In wireless Code Division Multiple Access (CDMA) system, the use of power control is indispensable to combat near-far and fading problems. Signals transmitted over a multipath propagation channel which exhibits inter-path interference and fading. The receiver has to employ measures to mitigate these effects or it will incur severe performance degradation. A classic approach in CDMA communicatio...

In DS-CDMA communications, the conventional receiver is the RAKE receiver. In the downlink (base station to mobile) signalling with celldependent scrambling, orthogonal codes and a common channel for all the users, this receiver does not maximize the Signal-to-Interference-plus-Noise Ratio (SINR) at its output. Another receiver, with the same structure as the RAKE receiver, is suitable for down...

In this paper, a software wireless communication simulator performed which simulates a Code division Multiple Access (CDMA) as Wireless cellular telephony has been growing at a faster rate than wired-line telephone networks. This growth has also been fueled by the recent improvements in the capacity of wireless links due to the use of multiple access techniques (which allow many users to share ...

In this paper, an advanced closed loop PolarizedMultiple-InputMultiple-Output Pre-RAKE Combined Transmit Diversity “Pol MIMO Pre-RAKE CTD” system is proposed for the downlink. The proposed system is designed and analyzed in frequency division duplex mode. The numerical results demonstrate that it can achieve a significant performance gain, especially for dense urban and suburban environments. T...

Performance analysis of multilevel unequal error protection (UEP) codes with wavelet video compression for wideband multicarrier code division multiple access (MC-CDMA) and Rake receivers over additive white Gaussian noise (AWGN) and Rayleigh fading channels are achieved and evaluated. Wavelets possess a dominant method and high quality for compressing video sequence. A spatially scalable video...