In this paper we consider the performance of a UTRA TDD system with various slot configurations. UTRA TDD supports flexible and dynamic channel allocations thus it can be configured to different service needs. Uplink and downlink transmissions have different characteristics and in this study we are concentrating on the requirements for symmetrical services in dedicated channels. Effect of numbe...

In this paper we analyse the performance of a relay based UMTS system in an urban environment using multiple hops on multiple frequency bands. Measurement based path loss, fading and shadowing models are used in the Manhattan grid deployment scenario. Both uplink and downlink operations of the cellular system are considered at the same time. Two hop communication links over the uplink and downl...

In antenna array systems, downlink beamforming and uplink maximum likelihood structured channel estimation can be formulated under a common framework related to the algebraic stucture of the two problems. The slow variations of the uplink and downlink spatial subspaces, due to moving terminals, can be tracked by using an adaptive structure based on a common processing block, namely a subspace t...

This letter introduces a joint design method for uplinkdownlink multiple-input multiple-output (MIMO) relay communication systems in which the source nodes transmit information to the destination nodes with the help of a relay. We propose a signal forwarding schceme based on the minimum mean-square error (MMSE) approach in uplink relay systems. Exploiting the duality of relay systems, we also p...

The rapid evolution of digital mobile data services exerted a need for serious thrust on more efficient ways to address the harmful effects of electromagnetic radiation due to the Uplink power of the mobile terminal on the human body. The Specific Absorption Rate (SAR) value is the standard dosimetric parameter in defining the energy absorbed by the human body exposed to EM radiation. Increase ...

I. MAX SUM-RATE SCHEDULING: THE UPLINK CASE We have seen (in the presentation) that, for downlink (broadcast) channels, the strategy maximizing the sum-rate is one which only transmits to the user with best channel reception [1]. We now present a similar result for uplink (multi-access) channels [2]. Consider the single-cell multiuser uplink scenario where the signal received by the base statio...

Blind adaptive space-time processing techniques are developed for both uplink reception and downlink transmission in multiuser TDD DS-CDMA systems to overcome multipath fading effect and multiple access interference. The system consists of a spacetime array, a decorrelator, and a weight-adapter. For uplink reception, a hybrid combination of constant modulus algorithm and decisiondirected algori...

In this paper, space-time block coding (STBC) is applied to single-carrier distributed antenna network (SC-DAN). By using the frequency-domain STBC coded joint transmit/receive diversity (FDSTBC-JTRD) for the downlink while using the well-known frequencydomain space-time transmit diversity (FD-STTD) for the uplink, the diversity order is given by the product of the number of distributed antenna...

Since in CDMA systems, to transmit with less power is essential for reducing neighbor cell interferences as well as saving battery of user terminals, transmit power minimization problem is an important issue to be considered. In [1], the model of transmit power minimization problem in CDMA systems uplink is presented. In this paper, we first review previous work, then investigate the transmit p...