The outage probability of a forward link DSCDMA cellular system with fast transmit power control (TPC) based on signal-to-interference ratio (SIR) is investigated. The expression for SIR at the output of RAKE receiver is developed, and the outage probability is evaluated by using Monte Carlo simulation. We consider two kinds of channel models: random delay resolvable path model and tapped delay...

Direct sequence code division multiple access (DSCDMA) using frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion has been attracting much attention as a promising wireless access technique in a frequency-selective fading channel. The conventional FDE requires the insertion of guard interval (GI) to avoid the inter-block interference (IBI). However, GI ins...

A class of unified multicarrier DS-CDMA (MC DS-CDMA) schemes is defined and its performance is considered over multipath Nakagamim fading channels. The spacing between two adjacent subcarriers of the unified MC DS-CDMA scheme is a variable, allowing us to gain insight into the effects of the spacing on the bit error rate (BER) performance of MC DS-CDMA systems. This unified MC DS-CDMA scheme in...

A sub-symbol based multiuser detector for DSCDMA systems was proposed in [1]. This paper addresses the optimization of such detectors to maximize the system capacity. It is shown that the maximum number of simultaneous users supported in a DS-CDMA system using sub-symbol scheme can be increased by the proper selection of certain thresholds delineated in [1], and by imposing moderate synchroniza...

We examine the outage probability of a multi-code DSCDMA system with Minimum Mean Squared Error (MMSE) linear interfenxce suppression. Multi-code DS-CDMA allows different information mtes by varying the number of spreading codes assigned to each user. Power control is used to achieve a set of taryet Signal-to-Inter ference-plus-Noise Ratios (SINRS), and an outage occurs if a user must incnmse t...

Introduction: Blind adaptive linear receivers for DS-CDMA have been proposed in recent years to supress multiple acess interference (MAI) [1–4]. Blind solutions for flat channels based on the minimum variance (MV) and the constant modulus (CM) criterion have been reported in [1] and [2]. Recently, constrained minimum variance (CMV) and constrained constant modulus (CCM) adaptive linear receiver...

Bit error rate (BER) performance of DS-CDMA receiver which consists of a RAKE receiver followed an adaptive MLSE diversity receiver is proposed to simultaneously suppress multi user interferences and multi path fading interferences. A new adaptive equalization in the channel estimator and predictor of MLSE receiver is introduced. RLS algorithm is used for adaptive channel estimator. The Euclide...

In this paper we present low-complexity blind multi-input multi-output (MIMO) adaptive linear multiuser receivers for direct sequence code division multiple access (DSCDMA) systems using multiple transmit antennas and spacetime block codes (STBC) in multipath channels. A spacetime code-constrained constant modulus (CCM) design criterion based on constrained optimization techniques and low-compl...

The paper addresses the blind equalization problem of spread spectrum modulations in the presence of fast time-variant frequency selective channels. The basic assumption of the paper is that the channel response exhibit fast changes. A second goal of the paper is to force the definition of a universal CDMA blind equalization scheme that is capable to perform for DSCDMA or Multi-Carrier CDMA sig...

The cyclostationary properties of Direct Sequence Spread Spectrum signals are well known. These cyclostationary properties imply a redundancy between frequency components separated by multiples of the symbol rate. In this paper we present a Multiple Access Interference Canceller that explores this property and applies to UMTS-TDD. This frequency domain Canceller acts in the spreaded signal in s...