The WiMAX forum is based on 802.16d/e Orthogonal Frequency Division Multiplexing (OFDM) based adaptive Physical Layer (PHY) layer. In this paper, the performance of WiMAX PHY layer is investigated for two PHY layer modifications, link adaption algorithm (Adaptive Modulation and coding, AMC) and MCCDMA (hybrid OFDM system with multiple access technology, Code Division Multiple Access) to provide...

Time variations of the mobile radio channel cause InterCarrier Interference (ICI) to Orthogonal Frequency Division Multiplexing (OFDM) and Multi-Carrier CDMA (MCCDMA) radio links. This paper evaluates the effect of Doppler and delay spreads on the performance of an MC-CDMA receiver. An MMSE receiver is analyzed for MC-CDMA transmission over a mobile channel with Doppler. A simplified, pseudo MM...

In this paper we consider the uplink transmission in MCCDMA systems (MultiCarrier Coded Division Multiple Access). To reduce the envelope fluctuations of the transmitted signals, the MC-CDMA signal associated to each MT (Mobile Terminal) is submitted to a clipping device,followed by a frequency-domain filtering operation. We define an iterative receiver that jointly performs the MUD (MultiUser ...

In this paper we introduce an enhanced DQRUMA/ MC-CDMA protocol for wireless packet networks. The original DQRUMA/MC-CDMA protocol may suffer severe code collisions due to a limited number of request codes. An enhanced DQRUMA/MC-CDMA protocol using minislots for request accesses is proposed to reduce request collisions. In the proposed protocol, request attempts can be transmitted concurrently ...

This paper presents an overview of the effect of synchronisation errors on MCCDMA performance in downlink communications. We distinguish two types of synchronisation errors: carrier phase errors and timing errors. We show that the MC-CDMA system is very sensitive to a carrier frequency offset or a clock frequency offset. For a maximal load, carrier phase jitter and timing jitter give rise to a ...

In this contribution, the benefit of applying channel knowledge at the transmitter is investigated for multi-carrier spread-spectrum (MC-SS) systems. Two different MC-SS systems are observed, namely uplink multi-carrier code-division multiple-access (MCCDMA) and spread-spectrum multi-carrier multiple-access (SSMC-MA). The latter system is considered for both downand uplink transmission. Pre-equ...

The Maximum Likelihood joint detection of all users in a Multi-Carrier Code Division Multiple Access (MCCDMA) system has a prohibitive complexity, growing exponentially with the number of users, when it is performed using an exhaustive search. In this paper, a novel ML multiuser detection algorithm is proposed, whose complexity is a polynomial function of the number of users and is independent ...

Similar to direct sequence code division multiple access (DS-CDMA), site diversity can be applied to a multicarrier-CDMA (MCCDMA) cellular system to improve the bit error rate (BER) performance for a user with weak received signal power, thus resulting in an increased link capacity. In this paper, the downlink site diversity reception using frequency-domain equalization based on minimum mean sq...

Multi Carrier Code Division Multiple Access (MC-CDMA) is a well known technique for high speed wireless data transmission .Two advanced technology was included in the MC-CDMA structure, such as orthogonal frequency division multiplex (OFDM) and the code division multiple access (CDMA),so that it benefits from the robustness of OFDM against multipath environment and from the capability of multiu...