Single-Carrier Frequency Division Multiple Access (SC-FDMA) has been selected as the uplink transmission scheme in the 3GPP Long Term Evolution standard. SC-FDMA is a form of Single-Carrier Frequency Domain Equalization (SCFDE) with flexibility in its resource allocation. In this paper we investigate the performance of SC-FDMA with Frequency-Domain Linear Equalization (FD-LE) with optimized transmit power allocation. We derive the optimum power allocation for both Zero-Forcing (ZF) and Minimum Mean-Square Error (MMSE) FD-LE receivers in order to maximize the achievable data rate subject to total transmit power constraint. Results show that optimum transmit power allocation given knowledge of the FD-LE receiver results in a better achievable transmission rate compared to the information theoretic optimum transmit power allocation, which assume an ideal receiver. Results show that the proposed power allocation scheme offers significant increases in the operating range and cell throughput of SC-FDMA system.

Performance of SC-FDMA with transmit power allocation and Frequency-Domain Equalization

Single-Carrier Frequency Division Multiple Access (SC-FDMA) has been selected as the uplink transmission scheme in the 3GPP Long Term Evolution standard. SC-FDMA is a form of Single-Carrier Frequency Domain Equalization (SC-FDE) with a flexibility in resource allocation, thus it has reduced sensitivity to phase noise and a lower Peak-to-Average Power Ratio (PAPR) compared to Orthogonal Frequency Division Multiple Access. This, consequently, makes it more attractive for low cost devices with limited transmit power. In this paper we propose an optimum power allocation scheme for SC-FDMA transmission considering Frequency-Domain Linear Equalization (FD-LE). We derive the optimum power allocation for the SC-FDMA transmission for both a Zero-Forcing (ZF) and a Minimum Mean-Square Error (MMSE) receiver in order to maximize the achievable rate subject to a constant transmit power. Results show that the optimum power allocation for the MMSE FD-LE results in greater improvement in the achievable transmission rate compared to ZF FD-LE.

Optimum transmit filter for Single-Carrier FDMA with Frequency-Domain Linear Equalization

This master thesis investigates several di®erent channel estimation techniques in an SC-FDMA (Single Carrier Frequency Division Multiple Access) system with parameters setaccording to the s ...

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Channel Estimation Techniques of SC-FDMA

This article aims to establish a performance comparison between the single-carrier with cyclic prefix (SCCP) and the orthogonal frequency division multiplexing (OFDM) for frequency selective block fading channels without channel information on the transmitter side and using error correcting codes. For the SCCP scheme, it will be considered both linear and decision-feedback equalizers implementations. We will assess both schemes bit-error rates and capacities for different modulations and coding rates using different approaches. Firstly, analytical results are obtained for a convex analysis framework based on the OFDM effective signal-to-noise ratio and the cutoff rate together with the Shannon capacity analysis. In addition, Monte Carlo simulations are evaluated, corroborating previous analytical results and giving further insights on the comparison.

/pdf/a-comparison-between-ofdm-and-single-carrier-with-cyclic-anaomc47kj.pdf

A comparison between OFDM and single-carrier with cyclic prefix using channel coding and frequency-selective block fading channels

There is considerable interest in the use of Single Carrier Frequency Division Multiple Access (SC-FDMA) as the uplink transmission scheme in the 3GPP Long Term Evolution standard. This interest is justified by the inherent single carrier structure of SC-FDMA, which results in reduced sensitivity to phase noise and a lower Peak-to-Average Power Ratio (PAPR) compared to Orthogonal Frequency Division Multiple Access. This, consequently, makes it more attractive for low cost devices with limited transmit power. In this paper we demonstrate how precoding the uplink transmission is an alternative signal processing technique to equalization in order to combat the frequency selective nature of the propagation channel. The frequency-domain implementation of Tomlinson-Harashima Pre- coding (THP) for uplink SC-FDMA is proposed. We investigate the BER performance and the PAPR characteristics of the precoded SC-FDMA waveform for ZF and MMSE based THP. Results reported here show that the MMSE-THP outperforms the ZF-THP in terms of BER performance and PAPR. Index Terms: 3GPP LTE, SC-FDMA, Tomlinson-Harashima Pre- coding, PAPR, Equalization.

/pdf/a-novel-frequency-domain-implementation-of-tomlinson-avh0hk0oga.pdf

A Novel Frequency-Domain Implementation of Tomlinson-Harashima Precoding for SC-FDMA

Computational complexity and error propagation phenomenon are important drawbacks of existing Decision Feedback Equalizers (DFE) for dispersive channels. A new Iterative Block DFE (IBDFE) is considered where the equalization is performed iteratively on blocks of received signal in the frequency domain i.e. both signal processing and filter design are in frequency domain. Thus computational complexity is reduced and error propagation is limited to one block. The feed forward and feedback filters of DFE are designed with the minimization of Mean Square Error (MSE) at detector input as the parameter for effective detection. Two design methods have been solved and simulated for a Rayleigh fading channel. Channel is assumed to be time in-variant during one block of data (128 symbols) transmission. In the first method, the hard detected data are used as the input to the feedback, and filters are designed according to the correlation between detected and transmitted data. In the second method, the feedback signal is directly designed from soft detection of the equalized signal at the previous iteration. Estimates of the parameters involved in the FF and FB filters are also solved and used to evaluate the filter coefficients. From simulation, it was found that the IBDFE as claimed in the research literature performs better than the time domain DFE.

http://ieeexplore.ieee.org/iel5/5191366/5204362/05204497.pdf

V. Noormohammed

Papers

Frequency domain equalization for single carrier wireless systems