An analysis of two-dimensional pilot-symbol assisted modulation for OFDM

Nilsson, Rickard; Edfors, Ove; Sandell, Magnus; Börjesson, Per Ola

doi:10.1109/icpwc.1997.655481

Cited by 57 publications

(49 citation statements)

References 7 publications

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“…For comparison, Fig. 2 also depicts the MSE with the use of the optimum 3-D Wiener CEF, and two 1-D Wiener CEFs optimized for a SISO scheme in the time and frequency domain [1], [2]. It can be seen that the proposed scheme can provide near optimum CE performance, while the use of conventional two 1-D Wiener CEFs suffers from performance degradation especially when the channel has strong spatial correlation and the SINR is low.…”

Section: Performance Evaluationmentioning

confidence: 99%

“…In this case, the filtering in the frequency domain is done once per d t symbols in Fig. 1, requiring (d f + N f d t ) multiplications per symbol to obtain the CIR corresponding to the data symbol for each pair [2]. Finally, the CIR can be obtained by combining MN CIRs estimated from all antenna pairs.…”

Section: Proposed Cefmentioning

confidence: 99%

“…Assuming each path has the same normalized time-correlation function r t (∆i) with different average power σ 2 l , the correlation can be decomposed as [1], [2] …”

Section: Copyright C 2007 the Institute Of Electronics Information Amentioning

confidence: 99%

“…However, it results in performance degradation compared to the 3-D Wiener CEF and only considers the correlation between the receive antennas. In this letter, extending the idea in [1], [2] of employing separate CEFs in each domain to MIMO-OFDM systems, we propose a low-complexity Wiener filter structure where Wiener filtering is performed independently in each domain with near optimum performance. Following Introduction, the system and channel model are described in Sect.…”

Section: Introductionmentioning

confidence: 99%

“…To increase the throughput of OFDM, it is crucial to accurately measure the channel impulse response (CIR). For a single-input single-output (SISO) system, a number of 2-dimensional (2-D) channel estimation (CE) schemes have been studied, where the channel correlation in the time and frequency domain is widely considered [1], [2].…”

Section: Introductionmentioning

confidence: 99%

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Complexity-Reduced Channel Estimation in Spatially Correlated MIMO-OFDM Systems

Choi¹,

Lee²

2007

IEICE Transactions on Communications

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SUMMARYThe performance of a MIMO-OFDM system significantly depends upon the accuracy of the channel impulse response (CIR) estimates. In the presence of correlation between the CIRs of the transmit or receive antennas, it is desirable to exploit this correlation to improve the performance of CIR estimation. In this letter, we propose a low-complexity channel estimation filter composed of four concatenated one-dimensional Wiener filters which are optimized to the channel characteristics in the time and frequency domains, and the transmit and receiver antenna front ends, respectively. Finally, the performance of the proposed scheme is verified.

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Section: Performance Evaluationmentioning

confidence: 99%

Section: Proposed Cefmentioning

confidence: 99%

“…Assuming each path has the same normalized time-correlation function r t (∆i) with different average power σ 2 l , the correlation can be decomposed as [1], [2] …”

Section: Copyright C 2007 the Institute Of Electronics Information Amentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Complexity-Reduced Channel Estimation in Spatially Correlated MIMO-OFDM Systems

Choi¹,

Lee²

2007

IEICE Transactions on Communications

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Reducing ICI effect in OFDM system using low‐complexity Kalman filter based on comb‐type pilots arrangement

Mousa¹,

Mahmoud²

2010

Int J Communication

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SUMMARYIn OFDM systems, time-varying channels destroy orthogonality between subcarriers causing Inter-Carrier Interference. To reduce this effect, a Kalman filter, as a benchmark, is used for channel estimation, based on comb-type pilot arrangements of the OFDM system. An advantage of comb-type pilot arrangements in channel estimation is the ability to track the variation of the channel caused by Doppler frequency. Kalman method has been proposed to estimate the channel frequency response (CFR) at the pilot locations, then CFR, at data subchannels, is obtained by means of interpolation between estimates at pilot locations. The low-complexity Kalman method is introduced to reduce the complexity of the system while achieving the same BER/SNR. Different types of interpolations have been also compared such as Low-pass, Splinecubic and Linear interpolation methods. The BER/SNR performance of BPSK modulation schemes are considered for time varying Rayleigh fading channels. Our results has shown that the low-complexity Kalman estimation, used with the pilot arrangement and a suitable interpolation method, gives almost the same performance as that of the Kalman method specially for low SNR values and hence the effect of Doppler shift effect is controlled.

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