The adoption of multiple antennas both at the transmitter and the receiver will explore additional spatial resources to provide substantial gain in system throughput with the spatial division multiple access (SDMA) technique. Optimal multiuser MIMO linear precoding is considered as a key issue in the area of multiuser MIMO research. The challenge in such multiuser system is designing the precod...

In this review paper, we analyze the performance of Channel estimation problem for TD-SCDMA System. The conventional channel estimation algorithm currently used in the TD-SCDMA system. Parallel interference cancellation (PIC) channel estimation algorithm by simultaneously eliminating the interference of adjacent cells and improve the accuracy of channel estimation. Accurate information of chann...

This thesis mainly studies the downlink of a wireless multiuser system, where the transmitter has limited knowledge about the communication channels of the users. Key techniques to improve the performance of such systems are, for instance, multiple antennas, multiuser diversity and orthogonal frequency-division multiple access (OFDMA). Common for these techniques is that, to exploit them fully,...

ADAPTIVE DS-CDMA MULTIUSER DETECTION FOR TIME VARIANT FREQUENCY SELECTIVE RAYLEIGH FADING CHANNEL

detection of multiuser signals, coupled with associated challenges in achieving this potential at affordable receiver complexity, has motivated significant amount of research to be carried out in the area of multiuser detection (MUD) in the past two decades. Much of the early research in this important area has been centered around systems employing code division multiple access (CDMA) promisin...

In this paper, we study an innovative multiple access scheme that exploits the intrinsic properties of the wireless environment to improve the multiuser environment, so-called Channel Division Multiple Access (ChDMA) focusing on spectral efficiency analysis and system performance. In particular, we show that Simultaneous multiuser accessing to a common destination is made possible by considerin...

The future wireless communications systems should be able to offer wide variety of applications, which have vastly different quality of service (QoS) requirements. The time-variable QoS may require the support of variable bit rates on the wireless links to the individual users. Multi-rate DS/CDMA is a promising basis on which to support the variable bit rates on the individual wireless links. C...

Problem statement: Multiple Input and Multiple Output (MIMO) system with Multihop relaying techhnique is significant and active areas of wireless communication. In a rich scattering environment MIMO antenna system provides better channel capacity and data rates than single antenna systems. To provide high throughput, reliable transmission and broad coverage, wireless relaying techniques are ess...

Limited feedback enables the practical use of channel state information in multiuser multiple-input multiple-output (MIMO) wireless communication systems. Using the limited feedback concept, channel state information at the receiver is quantized by choosing a representative element from a codebook known to both the receiver and transmitter. Unfortunately, achieving the high resolution required ...