Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
Adaptive channel tracking algorithms are studied based on LMS and KALMAN in MIMO-OFDM system. A novel adaptive channel tracking algorithm, which combines the LMS and KALMAN filter to make use of the stabilization of LMS and the accuracy of KALMAN filter, is proposed. On the one side, the algorithm can track and estimate the channel with the optimal MSE, and on the other hand, the algorithm conquers...
Multiantenna wireless systems have been well studied in achieving high data rates. In this paper, we improve a subspace-based blind channel estimation technique for multi- input multi-output (MIMO) orthogonal frequency-division multiplexing (OFDM) approach based on tracking the subspace recursively. The recursive subspace algorithm has a computational complexity of O(J2) , where the J is the input...
This paper mainly focus on methods for obtaining the CIR by performing the IFFT of CFR, which are heuristic or direct to improve channel estimation and tracking in MIMO- OFDMA systems. When FUSC mode is used, pilot signal are uniformaly inserted into the carrier sets during preamble and the FFT size over pilots spacing is an integer in mobile WiMAX. Therefore, it is possible to obtain CPR based on...
Multiple-input multiple-output (MIMO) receive antenna selection without channel state information (CSI) for linear detection is proposed in the presence of unknown interferences. This antenna selection technique is implemented based on training sample sequence by minimizing the Least Squares (LS) estimation error, which avoids the channel estimation. Since the high complexity of the exhaustive search,...
This paper reports on investigations into the effects of spatial correlation on channel estimation and capacity of a multiple input multiple output (MIMO) system. Minimum mean square error (MMSE) method is applied for channel estimation under a correlated channel scenario. Simulation results for a 4 times 4 MIMO system with the Jakes model describing a channel between a base station and a mobile station...
In reality, this is no such thing as perfect channel estimation. But unfortunately, channel estimation errors have never been taken into account by existing soft-output minimum mean square error (MMSE) multiple-input multiple-output (MIMO) detector when calculating the log-likelihood ratio (LLR) for coded bits, i.e., the soft information. As a result, its performance can be substantially degraded...
High peak-to-average power ratio (PAPR) is a disadvantage of comb-type frequency-domain training pattern (FDTP) in MIMO OFDM system. To deal with such problem, an excellent orthogonal time-domain training pattern (TDTP), based on circularly shifting Chu sequence and satisfying that optimal condition derived by us, is proposed for maximum likelihood (ML) channel estimation. From theory analysis and...
In this paper, we study the effect of channel estimation error at the receiver on the mutual information of a multiple-input-multiple-output (MIMO) channel obeying correlated Rayleigh fading. The system model is constructed based on the channel estimation error at the receiver side. And using the properties of Wishart distribution, the lower bound on the channel capacity is derived when the MIMO channel...
The researches about conditions of the resource allocation algorithm in wireless communication have been done a lot recently. An evaluation model for the adaptive algorithm of MIMO-OFDM system is built in this paper. After formulating system efficiency under static and adaptive conditions, the effect of imperfect channel state information (CSI) to MIMO-OFDM system is analyzed. Analytical and numerical...
This paper proposes a coarse time synchronization method which reduces the influence of the inter symbol interference(ISI) for MIMO-OFDM systems. The proposed method extracts the timing which is not disturbed by delay spread within the guard interval (GI) by utilizing the cyclic prefix (CP). Thus, the proposed method is effective in reducing the influence of the ISI. Simulation results demonstrate...
The combination of MIMO (Multiple Input Multiple Output) and OFDM (Orthogonal Frequency Division Multiplexing) is considered as a key technology of next wireless communication. In this paper, a MIMO-OFDM benchmark compliant to IEEE 802.16e standard is developed and evaluated on YHFT-DSP/700. We provide a detailed a detailed analysis of computation requirement, parallelism, memory requirement and intrinsic...
Multiple transmit-and-receive antennas can be used in orthogonal frequency division multiplexing (OFDM) systems to improve communication quality and capacity. In this paper, an improved channel estimation for MIMO-OFDM system is proposed by exploiting a new method of pilot insert by which pilots are inserted into different carriers at different time. The method can estimate the CSI of all frequencies,...
Perfect channel state information (CSI) is always assumed in work on multiple-input, multiple-output (MIMO) precoding theoretical analyze. In this paper, we investigate the effect of imperfect channel state information on the performance of MIMO broadcast channel (MIMO-BC). We show that even with moderate channel estimation error, the system performance degrade significantly. So, we propose a Frobenius...
This paper deals with the problem of time-varying (TV) channel estimation for multiple-input multiple-output/orthogonal frequency-division multiplexing (MIMO/OFDM) systems based on superimposed training (ST). The time-varying coefficients of the TV channel are firstly modeled by truncated discrete Fourier bases, and then optimally estimated both in one OFDM symbols and over multiple OFDM symbols by...
We propose in this paper a non-cyclic prefixed multiple-input multiple-output orthogonal frequency division multiplexing (non-cp MIMO-OFDM) system based on a recursive algorithm of joint channel estimation and data detection. Unlike in the traditional cyclic prefixed MIMO-OFDM system, the transmitted sequence of the proposed system is given in the way that block-type pilot sequences and OFDM symbols...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.