Performance of precoded OFDM with channel estimation error

Ahmed, Khawza I.; Tepedelenlioğlu, Cihan; Spanias, Andreas

doi:10.1109/tsp.2005.862898

Cited by 19 publications

(16 citation statements)

References 18 publications

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“…Replacing the channel estimateĥ = h − e in the received signal vector r = X D h + n, we have r = X Dĥ +n where we define the effective noise termn = X D e + n. Under the assumption of Gaussian channel estimation errors, an upper PEP bound for transmitted codeword matrix X D and erroneously decoded codeword matrixX D is given by 4 [11], [36] …”

Section: Appendix Amentioning

confidence: 99%

Impact of imperfect channel estimation on the performance of amplify-and-forward relaying

Gedik¹,

Uysal

2009

IEEE Trans. Wireless Commun.

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Abstract-In this paper, we investigate the error rate performance of amplify-and-forward (AF) relaying with imperfect channel estimation. We consider a single-relay scenario with orthogonal and non-orthogonal AF (OAF and NAF) cooperative protocols. Two pilot-symbol-assisted receiver architectures are studied: In the mismatched-coherent receiver, the complex fading channel coefficients (i.e., both phase and amplitude) are estimated based on a linear minimum-mean-squared-error estimation approach and fed to a coherent sub-optimal maximum likelihood decoder as if the channels were perfectly known. In the partiallycoherent receiver, channel amplitude is ignored and phase is estimated by a phase locked loop. For both receiver types, we analyze the achievable diversity orders for cooperative protocols under consideration and quantify the impact of channel estimation through the derivation of pairwise error probability. Our performance analysis reveals that a second order diversity order is obtained for the considered single-relay scenario indicating that full diversity is extracted. Our simulation results demonstrate that the performance degradation due to channel estimation with respect to the genie bound (i.e., perfect channel state information) is as small as 1.1dB based on the employed detector. Performance results further show that partially-coherent receiver presents a similar performance to mismatched-receiver for sufficiently large loop SNRs although channel amplitude is completely ignored.

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Section: Appendix Amentioning

confidence: 99%

Impact of imperfect channel estimation on the performance of amplify-and-forward relaying

Gedik¹,

Uysal

2009

IEEE Trans. Wireless Commun.

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“…Channel estimation errors are usually inevitable and might have significant impacts on system performance when the Doppler frequency is high. The performance of precoded orthogonal frequency division multiplexing (OFDM) systems with channel estimation error is studied in [4]. It is shown in [5] that for a single-input multiple-output (SIMO) system with identically and independently distributed (i.i.d.)…”

Section: Introductionmentioning

confidence: 99%

“…fading, the conventional maximal ratio combining (MRC) receiver is no longer optimum with imperfect CSI. The results of [4] and [5] cannot be applied to high-mobility systems because they both assume the systems experience quasi-static fading channels. The optimum designs of high-mobility systems in the presence of imperfect CSI are studied in [6,7] and [8] in terms of different design metrics, such as the bit error rate (BER), symbol error rate (SER), or spectral efficiency.…”

Section: Introductionmentioning

confidence: 99%

Energy and spectral efficient Doppler diversity transmissions in high-mobility systems with imperfect channel estimation

Zhou

Fan

2015

J Wireless Com Network

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This paper studies energy and spectral efficient Doppler diversity transmissions in the presence of imperfect channel state information (CSI). Fast time-varying fading in high-mobility communication systems introduces Doppler diversity that can benefit system performance. On the other hand, it is more difficult to estimate and track fast time-varying channel; thus, channel estimation errors might seriously degrade system performance in high-mobility systems. The trade-offs between channel estimation errors and Doppler diversity are studied by using two precoding schemes, a simple repetition code, and a rate 1 Doppler domain multiplexing (DDM) scheme. The repetition code can achieve the maximum Doppler diversity at the cost of a lower spectral efficiency, and the DDM scheme can achieve the energy and spectral efficient Doppler diversity transmissions. Unlike many other Doppler diversity systems that assume perfect CSI, we explicitly consider the impacts of imperfect CSI on the design and performance of both precoding schemes. Optimum and suboptimum receivers for both schemes are developed by studying the statistical properties of channel estimation errors. The analytical error probabilities of the receivers are expressed as functions of a number of system parameters, such as the maximum Doppler spread, the percentage of pilot symbols for channel estimation, the energy allocation between the pilot and data symbols, etc. The analytical and simulation results indicate that both precoding schemes can achieve the maximum Doppler diversity order through the optimization of the various parameters, even in the presence of imperfect CSI.

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“…Recently, linear precoding or block spreading for OFDM has been proposed to introduce data symbol correlation among subcarriers so that the frequency diversity performance can be improved [10][11][12][13][14][15][16][17]. The principle of precoding or block spreading is to produce different linear combinations of the input data symbols through a unitary matrix and then modulate the precoded or block spread data symbols onto different subcarriers.…”

Section: Introductionmentioning

confidence: 99%

Parallel Packet Transmission Based on OFDM

Huang

Guo

2009

2009 IEEE Wireless Communications and Networking Conference

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Abstract-This paper proposes a parallel packet transmission (PPT) scheme based on orthogonal frequency division multiplexing (OFDM). The principle of the PPT scheme is to divide a packet into a number of smaller parallel packets, and transmit each smaller packet over an individual subcarrier of the OFDM symbols instead of spreading the data bits in a packet across a number of different subcarriers. It is proved theoretically that the proposed PPT scheme has higher average throughput than the conventional serial packet transmission without precoding. Furthermore, simulation results show that the OFDM system with PPT outperforms the precoded OFDM system with minimum mean squared error equalization in both uncoded and coded cases in terms of average throughput. The PPT scheme provides an alternative and simpler means to combat frequency-selective fading.

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Performance of precoded OFDM with channel estimation error

Cited by 19 publications

References 18 publications

Impact of imperfect channel estimation on the performance of amplify-and-forward relaying

Impact of imperfect channel estimation on the performance of amplify-and-forward relaying

Energy and spectral efficient Doppler diversity transmissions in high-mobility systems with imperfect channel estimation

Parallel Packet Transmission Based on OFDM

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