This paper presents interference suppression using a subband adaptive array (SBAA) for uplink space-time block coding (STBC) code division multiple access (CDMA) under a frequency selective fading (FSF) channel. The proposed scheme utilizes CDMA with STBC and a receive array antenna with SBAA processing at the receiver. The received signal is converted into the frequency domain before despreadi...

Recent advances in wireless communications have made use of MC-CDMA and OFDM techniques to allow for high data rate transmission. Rapid time variations of the wireless communication channel have a effect on the performance of multicarrier modulation. In this paper, we emphasis the Doppler spread and Computes its effect on the bit error rate (BER) for multicarrier code division multiple access (...

Orthogonal Frequency Division Multiple Access (OFDMA) is today a part of many standard specifications. Despite its attractive features, it has two main drawbacks when employed in the uplink: The high peak-to-average power ratio inherited from Orthogonal Frequency Division Multiplexing (OFDM) and the inherent frequency diversity loss. The loss of frequency diversity can be alleviated by precodin...

We discuss two newly proposed multiple-access control (MAC) protocols for multirate optical code-division multiple access (OCDMA) networks. The first protocol is slotted ALOHA/optical fast-frequency-hopping code-division multiple access (S-ALOHA/OFFH-CDMA), and the second is round-robin receiver–transmitter/optical fast-frequency-hopping code-division multiple access (R3/OFFH-CDMA). Our main su...

A full-diversity space-frequency block code (SFBC) for Single-Carrier Frequency-Division Multiple Access (SC-FDMA) systems is presented. The code is designed for 2 transmit antennas and preserves the low envelope fluctuations of SC signals. We prove the good performance of the proposed scheme over multiple-input multiple-output (MIMO) channels, both in static and in high-speed mobility scenarios.

In this deliverable intermediate results on multiple access and multiple antenna technologies for RESUE are described. We start with an introduction summarizing the requirements on the physical layer and multiple access technologies. The main part is dedicated to non-orthogonal multiple access, where we investigate the suitability of GFDM and IDMA for RESCUE requirements. We can show that both ...

In this paper we describe the IEEE 802.16 Orthogonal Frequency Division Multiplexing (OFDM) and the 802.16 Orthogonal Frequency Division Multiple Access (OFDMA), Medium Access Control (MAC) protocols, both of which are key elements of the Worldwide Interoperability for Microwave Access Forum (WiMAX) deployments. We also discuss the types of provisioning and Quality of Service (QoS) that can be ...

orthogonal frequency division multiplexing – interleave division multiple access (OFDM-IDMA) have been proposed for beyond third generation (B3G) and fourth generation (4G) communication systems. These system are based on iterative multiuser detection (MUD) techniques. The efficiency of these systems is dependent on the generation of efficient user specific interleavers on the basis of which th...

Abstract In direct sequence code division multiple access (DS-CDMA), frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion can be applied to exploit the channel frequency-selectivity and therefore achieves much improved bit error rate (BER) performance than using the conventional rake combining. Even if FDE is applied to DS-CDMA, however, the uplink BER perform...

Single Carrier Frequency Division Multiple Access (SC-FDMA) has been adopted for fourth generation (4G) mobile uplink transmission schemes because of its low Peak to Average Power Ratio (PAPR) as compared to that of Orthogonal Frequency-Division Multiple Access (OFDMA).Since SC-FDMA has low PAPR, it is sensitive to Carrier Frequency Offsets (CFOs) similar to that of OFDMA. To minimize and compe...