DFT Based Channel Estimation Methods for MIMO-OFDM Systems

In this paper, we investigate channel estimation in the context of the orthogonal frequency division multiplexing (OFDM) based HomePlug AV system using the channel models provided by the open power-line communication European research alliance (OPERA). In particular, for increasing the system data rate efficiency, the two proposed algorithms do not make use of known OFDM symbols but exploit the synchronization preamble available at the beginning of each frame. However, the spectrum of the preamble i) contains many band gaps where data is not available and ii) in the remaining spectrum data is highly fluctuating in power. By several simulations using OPERA channel models, we will show the significant performance of the two proposed schemes, that offer a trade-off between complexity and performance.

show abstract

“…They generalize the schemes discussed in [3], [4] when null subcarriers are present both at the spectrum's extremities and inside the spectrum.…”

Section: Two Channel Estimation Algorithmsmentioning

confidence: 94%

“…To overcome both these aspects two suitable CE algorithms, based on known schemes [3] and [4], have been identified. They exploit the STS and reconstruct the channel characteristics in correspondence of the notched carriers.…”

Section: Introductionmentioning

confidence: 99%

Preamble-based channel estimation in HomePlug AV systems

Altolini

Benvenuto

Pupolin

et al. 2012

2012 IEEE International Symposium on Power Line Communications and Its Applications

View full text Add to dashboard Cite

show abstract

“…This is the reason that the conventional BP-CE method can estimate four different CFRs in the 2×2 MIMO-OFDM channels at every preamble symbol in which four different combined CIRs are estimated separately by taking the auto-correlation for the cyclically shifted Chu-sequence [4]. However, when the non-Nyquist rate, the combined CFR estimation accuracy of using the conventional BP-CE and SP-CE methods are degraded significantly due to the mismatching of sampling rate between the transmission signal with N samples and received signal with M samples [7]. While the proposed method can keep higher CFR estimation accuracy which is almost the same as that for the Nyquist rate.…”

Section: Performance Evaluationsmentioning

confidence: 98%

“…By using the received signal R q j (m, n) and R q j (m, n + 1) given in (7) and the estimatedĈ p,q i, j (m, n) of which estimation method is proposed in Sect. 4, the SFBC decoded data Y j,x (m, n) and Y j,x (m, n + 1) (x = 1 or 2) which includes the data information D i (m, n) sent from UT i (source) as well as the self information data D j (m, n) sent from UT j (destination) can be given by the following equation,…”

Section: Proposal Of Two-way Relay System Of Using Sfbc Mimo-ofdmmentioning

confidence: 99%

“…From this fact, the channel estimation accuracy obtained by using the 2D-DFT interpolation method would be degraded especially at around the both ends of data subcarrier which corresponds to the borders between the data and null subcarriers (zero padding) due to the mismatching of sampling rate between the transmission signal with N samples and received signal with M samples. This phenomenon is called the border effect [7].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Proposal of channel estimation method for wireless two-way relay system of using SFBC MIMO-OFDM technique

et al. 2016

View full text Add to dashboard Cite

In a two-way relay communication system, two user terminals (UTs) can communicate and exchange their information data through a relay station by using two timeslots. To realize the two-way relay communication system, each UT is required to estimate channel frequency responses (CFRs) both for up and down links in two timeslots efficiently which be employed in the demodulation of the other user's information data with frequency domain equalization. To satisfy this requirement, this paper proposes a novel CFR estimation method for the wireless two-way relay communication system of using SFBC MIMO-OFDM technique. The salient feature of proposed CFR estimation method is to employ the maximum likelihood estimation method for the proposed scattered pilot subcarriers assignment which can achieve higher CFR estimation accuracy even in higher timevarying fading channel and when the transmission OFDM signal is sampled by the non-Nyquist rate. In the proposed system, the SFBC technique is also employed for the data subcarriers both for the pilot symbols including data subcarriers and data symbols consisting of all data subcarriers in the frequency axis to improve the bit error rate (BER) performance in the two-way relay system. From the computer B Tanairat Mata simulation results, this paper demonstrates the effectiveness of proposed two-way relay communication system of using SFBC MIMO-OFDM technique. To demonstrate the effectiveness of proposed two-way relay communication system of using SFBC MIMO-OFDM technique, this paper conducts various computer simulations as comparing with the conventional methods in higher time-varying fading channel. From the computer simulation results, this paper confirms that the proposed method even at the non-Nyquist rate can achieve higher channel estimation accuracy evaluated by the normalized mean square error (NMSE) and better BER performances by 5 and 22 times, respectively as comparing with the conventional methods when the normalized Doppler frequency ( f d T S ) is 10 −2 and the carrier to noise power ratio (C/N) is 25 dB.

show abstract