Analysis and Optimization of OFDMA Uplink Systems Over Time-Varying Frequency-Selective Rayleigh Fading Channels
نویسندگان
چکیده
In this paper, the performance of orthogonal frequency division multiple access (OFDMA) uplink systems over time-varying frequency-selective Rayleigh fading channels is investigated. Expressions of the bit error rate (BER) performance for quadrature phase shift keying (QPSK) and quadrature amplitude modulation (QAM) signals under channel estimation errors are derived. Based on BER performance, the optimum pilot insertion rates for a tile-based OFDMA system to maximize the overall system throughput is investigated.
منابع مشابه
Adaptive Switching between Space-Time and Space-Frequency Block Coded OFDM Systems in Rayleigh Fading Channel
This work explores the performances of Space-Time and Space Frequency Coded Orthogonal Frequency Division Multiplexing (OFDM) with simple two branches transmit diversity scheme. The combination of multiple-antenna and orthogonal frequency division multiplexing (OFDM) provides reliable communications over frequency selective fading channels. We focus on the application of space-time block codes ...
متن کاملSingle-Carrier Frequency-Domain Equalization for Orthogonal STBC over Frequency-Selective MIMO-PLC channels
In this paper we propose a new space diversity scheme for broadband PLC systems using orthogonal space-time block coding (OSTBC) transmission combined with single-carrier frequency-domain equalization (SC-FDE). To apply this diversity technique to PLC channels, we first propose a new technique for combining SC-FDE with OSTBCs applicable to all dispersive multipath channels impaired by impulsive...
متن کاملBit Error Performance for Asynchronous Ds Cdma Systems Over Multipath Rayleigh Fading Channels (RESEARCH NOTE)
In recent years, there has been considerable interest in the use of CDMA in mobile communications. Bit error rate is one of the most important parameters in the evaluation of CDMA systems. In this paper, we develop a technique to find an accurate approximation to the probability of bit error for asynchronous direct–sequence code division multiple–access (DS/CDMA) systems by modeling the multipl...
متن کاملInformation Theoretic Aspects of Multiuser Multicarrier Systems
This thesis deals with multiuser multicarrier communications over unknown time and frequency selective fading channels. Since there is a growing demand for capacity, especially in mobile communications, wireless multiuser communications experiences increasing interest in recent year. The wireless channel in general is a time and frequency selective fading channel. In that case, orthogonal frequ...
متن کاملA Unified Analysis for Direct-Sequence CDMA in the Downlink of OFDM Systems
This paper presents a unified analysis for the downlink BER performance of convolutionally coded and single-user detected MC-CDMA, MCDS-CDMA and TFL-CDMA. As a special case, an analysis is obtained also for OFDMA. The intra-cell interference is analyzed under the assumption of Hadamard spreading codes and a correlated frequency-selective Rayleigh-fading channel. The presented results assume err...
متن کامل