For high data rate ultra wideband communication system, performance comparison of Rake, MMSE and Rake-MMSE receivers is attempted in this paper. We have taken into account of impact of all the parameters such as the effect of the number of Rake fingers and equalizer taps on the error performance by combating ISI are the major focus of our research. The bit error rate performances are investigat...

Sistemele de comunicaţii de banda ultralargă (ultra wideband – UWB) se dovedesc a fi sisteme noi şi sigure pentru comunicaţiile fără fir, datorită capacităţii lor de a asigura comunicaţii de putere scăzută, cu rată mare de transmisie pe distanţe scurte, într-un mediu aglomerat în care avem un număr mare de căi multiple de propagare. Vom analiza şi compara performanţele a trei tipuri de receptoa...

In this paper, simplified RAKE receiver structures is analysed and its performance in UWB channels is studied. This paper also contains simulation and comparison of different types of RAKE receivers – ARAKE receiver, SRAKE receiver, and PRAKE receiver. The improvement in the bitrate for the specific distance between transmitter and receiver is shown here. The finger selection is one of the impo...

The conventional receiver for DS-CDMA communications is the RAKE receiver which is a matched filter (MF), matched to the operations of spreading, pulse shape filtering and channel filtering. The RAKE receiver assumes a sparse/pathwise channel model so that the channel matched filtering gets done pathwise, with delay adjustment and decorrelation per path and maximum-ratio combining of path contr...

Currently, a global third generation cellular system based on CDMA is being developed with a wider bandwidth than existing second generation system. The RAKE Receiver instead of completely eliminating multipath uses techniques to effectively utilize multipath to produce the desired signal. This paper proposes interference mitigation by CDMA RAKE receiver with WalshHadamard Sequence for DSCDMA s...

In this paper, the conditions and performance of ideal RAKE reception for time hopping UltraWideband (UWB) investigated. Owing to the complex propagation phenomena and specific structure of UWB signals, new problems relevant to the operation of RAKE receivers arise. This motivates us to reconsider the conditions under which a RAKE receiver can work effectively with negligible interference betwe...

The goal for the third generation of mobile communications system is to integrate a wide variety of communication services such as high speed data, video and multimedia traffic as well as voice signals. Under the Universal Mobile Telecommunication System (UMTS) environment the Third Generation (3G) has many advantages such as highly efficient spectrum utilisation and variable user data rates. I...

In order to solve the bit front rake angle parameter selection problem of under different coal rock, it is proposed in polycrystalline diamond compact no core bit as the research object, and established a bit compact two-dimensional stress model of cutting teeth. The result shows that the front rake angle is the factor of cutting force and the drilling efficiency. Application of Solid Works sim...

| The wideband code-division multiple access (CDMA) concept (FMA2) developed in the European FRAMES AC090 project supports variable data rate transmission. The data rate can be altered by changing either the spreading factor or by using multiple spreading codes in parallel. In order to facilitate exible changing of data rate, orthogonal Walsh codes are used for channel separation, followed by s...