Capacity Maximizing MMSE-Optimal Pilots for Wireless OFDM Over Frequency-Selective Block Rayleigh-Fading Channels

Ohno, Shûichi; Giannakis, Georgios B.

doi:10.1109/tit.2004.833365

Cited by 193 publications

(142 citation statements)

References 24 publications

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“…Note that this solution resembles the solution found in [19] but with a channel length of 2L instead of the length L due to the mirror channel introduced by the IQ imbalance.…”

Section: Optimal Pilot Power Allocationmentioning

confidence: 51%

“…However, in all of these pilot designs, the question of what is the optimal pilot power allocation in the presence of IQ imbalance hasn't been dealt with. In [19], the problem of optimal power allocation in OFDM systems where the channel is learnt through training was considered. However, it did not consider the effect of IQ imbalance in the OFDM system.…”

Section: Introductionmentioning

confidence: 99%

“…In this work, we consider a more general case of [19] where the OFDM system suffers from IQ imbalances and the IQ imbalance parameters are estimated in the form of the channel taps for both direct and mirror channels. When there are no amplitude and phase mismatches between the I and Q carriers, the mirror channel becomes zero, and the problem reduces to the problem as considered in [19]. Simulations show the improved capacity and reduced bit error rate (BER) as a result of using the optimal power allocation that we derived.…”

Section: Introductionmentioning

confidence: 99%

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Optimal Pilot Power Allocation for OFDM Systems with Transmitter and Receiver IQ Imbalances

Gottumukkala

Minn

2009

GLOBECOM 2009 - 2009 IEEE Global Telecommunications Conference

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Abstract-In this paper, we derive optimal pilot power allocation for OFDM systems suffering from in-phase and quadraturephase (IQ) imbalances. Existing works in literature on IQ imbalances optimize for pilot spacings and pilot designs. However, in all these works, optimal power allocation between pilot and data symbols has not been considered. Using a lower bound on the average channel capacity as a metric, we optimize for the pilot and data power allocations. Simulations show that the resulting optimal pilot power allocation increases the channel capacity along with lowering the bit error rate (BER). We further show that the power allocation is flexible in the sense that several power allocation choices exist that improve capacity compared to the equal power allocation scenario.

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“…Note that this solution resembles the solution found in [19] but with a channel length of 2L instead of the length L due to the mirror channel introduced by the IQ imbalance.…”

Section: Optimal Pilot Power Allocationmentioning

confidence: 51%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Optimal Pilot Power Allocation for OFDM Systems with Transmitter and Receiver IQ Imbalances

Gottumukkala

Minn

2009

GLOBECOM 2009 - 2009 IEEE Global Telecommunications Conference

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“…That case is beyond the scope of this study, and we assume that such a priori knowledge does not exist. A related study on optimal pilot arrangement in single antenna OFDM systems with block Rayleigh fading can be found in [23]. In addition, a detailed treatment of optimal pilot symbol-aided modulation (PSAM) in MIMO frequency-selective channels is given in [24].…”

Section: Overview Of Tdd System and Pilot Arrangementmentioning

confidence: 99%

Impact of Pilot Design on Achievable Data Rates in Multiple Antenna Multiuser TDD Systems

Samardžija¹,

Mandayam

2007

IEEE J. Select. Areas Commun.

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“…The MSE of the LMMSE channel estimate is given by From (16) [13], it can be readily verified that given constant total power, the average MSE …”

Section: A Channel Estimationmentioning

confidence: 99%

Analysis and Optimization of Pilot Symbol-Assisted Rake Receivers for DS-CDMA Systems

Cui

Tellambura

2006

IEEE Trans. Veh. Technol.

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Abstract-The effect of imperfect channel estimation (CE) on the performance of pilot-symbol-assisted modulation (PSAM) and MRC rake reception over time-or frequency-selective fading channels with either a uniform power delay profile (UPDP) or a nonuniform power delay profile (NPDP) is investigated. For time-selective channels, a Wiener filter or linear minimum mean square error (LMMSE) filter for CE is considered, and a closedform asymptotic expression for the mean square error (MSE) when the number of pilots used for CE approaches infinity is derived. In high signal-to-noise ratio (SNR), the MSE becomes independent of the channel Doppler spectrum. A characteristic function method is used to derive new closed-form expressions for the bit error rate (BER) of rake receivers in UPDP and NPDP channels. The results are extended to two-dimensional (2-D) rake receivers. The pilot-symbol spacing and pilot-to-data power ratio are optimized by minimizing the BER. For UPDP channels, elegant results are obtained in the asymptotic case. Furthermore, robust spacing design criteria are derived for the maximum Doppler frequency.Index Terms-Channel estimation (CE), direct-sequence codedivision multiple access (DS-CDMA), maximal ratio combining (MRC), Wiener filter.

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Capacity Maximizing MMSE-Optimal Pilots for Wireless OFDM Over Frequency-Selective Block Rayleigh-Fading Channels

Cited by 193 publications

References 24 publications

Optimal Pilot Power Allocation for OFDM Systems with Transmitter and Receiver IQ Imbalances

Optimal Pilot Power Allocation for OFDM Systems with Transmitter and Receiver IQ Imbalances

Impact of Pilot Design on Achievable Data Rates in Multiple Antenna Multiuser TDD Systems

Analysis and Optimization of Pilot Symbol-Assisted Rake Receivers for DS-CDMA Systems

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