A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computationally complexity algorithms," in Proceedings of IEEE International Conference of Acoustics, Speech and Signal Processing, (Denver), pp. 964--967, April 1980.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....systems with respect to ISI ICI. 1. INTRODUCTION Background. Orthogonal frequency division multiplexing (OFDM) is an attractive modulation scheme for high data rate wireless communications [1 3] Conventional OFDM, which employs rectangular transmit receive pulses and a cyclic prefix (CP OFDM) [2], is part of the standards IEEE 802.11a, Hiperlan 2, DAB T, and DVB T and is being considered for broadband wireless access by the IEEE 802.16 standardization work group. OFDM is also a promising candidate for future cellular communication systems. Pulse shaping OFDM systems and biorthogonal ....

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," in Proc. IEEE ICASSP-80, (Denver, CO), pp. 964--967, 1980.

....loss generality, this approach can be applied to the other DSL systems as well. CHAPTER THREE DMT ADSL CHANNEL MODULATION AND CHARACTERISTICS 3. Discrete Multitone Modulation System and ADSL Discrete Multitone (DMT) is a common form of multicarrier modulation. It has been introduced by IBM [27] to take advantage of digital signal processing and the FFT. It was later refined to a very high performance form [28] 29] That later form is used in the most recent multicarder voiceband modems, such as ADSL [30] DMT is a method to approximate the channel complex filters by simpler ....

A. Peled and A. Ruiz, "Frequency Domain Data Transmission Using Reduces Computational Complexity Algorithms," International Conference on Acoustics, Speech, and Signal Processing, April 1980, pp. 964-967.

....interference (ICI) multicarrier transmission, cyclic prefix, time domain equalization. I. INTRODUCTION N this paper, we address the impact of a too short cyclic prefix in multicarrier systems [1] The cyclic prefix removes the intersymbol interference (ISI) and intercarrier interference (ICI) [2]. The introduction of the cyclic prefix of length , see Fig. 1, gives a constant capacity loss, since the channel does no longer carry data for short periods of time. As such, one would like to minimize the length of the cyclic prefix, preferably maintaining performance. Common wisdom is to ....

Peled, A. and Ruiz, A., `Frequency domain data transmission using reduced computational complexity algorithms', Proc. IEEE ICASSP, pp. 964--967, Denver, Colorado, 1980.

....in low rank approximations of the LMMSE. Section IV is devoted to symbol error rate (SER) comparisons. A summary and concluding remarks appear in Sec tion V. II. SYSTEM DESCRIPTION Figure I displays the OFDM base band model used in this paper. We assume that the use of a cyclic pre fix [8] both preserves the orthogonality of the tones and eliminates inter symbol interference between consecutive OFDM symbols. Further, the channel is assumed to be slowly fading, i.e. it is considered to be constant during the transmission of one symbol. The number of tones in the system is N, and ....

A. Peled and A. Ruiz. Frequency domain data transmission using reduced computational complexity algorithms. In Proc. IEEE ICASSP, pages 964-967, Denver, Colorado, 1980.

....inherent in low rank approximations of the LMMSE. Section 4 is devoted to symbol error rate (SER) comparisons. A summary and concluding remarks appear in Section 5. II. System description Figure 1 displays the OFDM base band model used in this paper. We assume that the use of a cyclic prefix [8] both preserves the orthogonality of the tones and eliminates inter symbol interference between consecutive OFDM symbols. Further, the channel is assumed to be slowly fading, i.e. it is considered to be constant during the transmission of one symbol. The number of tones in the system is N , and ....

A. Peled and A. Ruiz. Frequency domain data transmission using reduced computational complexity algorithms. In Proc. IEEE ICASSP, pages 964--967, Denver, Colorado, 1980.

....The proposed low rank estimator is compared to other estimators in Section V and a summary and concluding remarks appear in Section VI. II. SYSTEM DESCRIPTION A. System Model Fig. 1 displays the OFDM baseband model used in this paper. We assume that the use of a cyclic prefix (CP) [9] both preserves the orthogonality of the tones and eliminates intersymbol interference (ISI) between consecutive OFDM symbols. Further, the channel is assumed to be slowly fading, so it is considered to be constant during one OFDM symbol. The number of tones in the system is N and the length of ....

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," in Proc. IEEE lnt. Conf Acoustics, Speech, and Signal Processing, Denver, CO, 1980, pp. 964-967.

....systems with respect to ISI ICI. 1. INTRODUCTION Background. Orthogonal frequency division multiplexing (OFDM) is an attractive modulation scheme for high data rate wireless communications [1 3] Conventional OFDM, which employs rectangular transmit receive pulses and a cyclic prefix (CP OFDM) [2], is part of the standards IEEE 802.11a, Hiperlan 2, DAB T, and DVB T and is being considered for broadband wireless access by the IEEE 802.16 standardization work group. OFDM is also a promising candidate for future cellular communication systems. Pulse shaping OFDM systems and biorthogonal ....

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," in Proc. IEEE ICASSP-80, (Denver, CO), pp. 964--967, 1980.

....even more attractive since both modulation and demodulation can be performed using computationally efficient Fast Fourier Transforms (FFT) of finite length, # . The orthogonality of the consecutive OFDM symbols is maintained by appending a length # cyclic prefix (CP) at the start of each symbol [1]. The CP is obtained by taking the last # samples of each symbol and consequently the total length of the transmitted OFDM symbols is ## # ## samples. For each OFDM symbol to be independent and to avoid any Inter Symbol Interference (ISI) or Inter Carrier Interference (ICI) the length of the ....

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computationally complexity algorithms," in Proceedings of IEEE International Conference of Acoustics, Speech and Signal Processing, (Denver), pp. 964--967, April 1980.

....modeled as otherwise (1) where is the index set for the upstream carriers, is the total number of subcarriers, is the length (in samples) of the cyclic prefix, is the length of the cyclic suffix, is the QAM data, and is the sampling frequency. The cyclic suffix is, similar to the cyclic prefix [9], a cyclic extension of the DMT symbol at the end of the symbol. The cyclic suffix is required to make the near echo orthogonal to the received signal. Its length has to be at least as long as the propagation delay of the longest wire in the system. If all modems in the network are synchronized ....

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," in Proc. IEEE Int. Conf. Acoustics, Speech, Signal Processing, Denver, CO, 1980, pp. 964--967.

....of finite length for modulation and demodulation. Among the standards that have placed their confidence in OFDM are HIPERLAN 2 [1] and IEEE 802.11 a [2] The orthogonality of the consecutive OFDM symbols is maintained by appending a length cyclic prefix (CP) at the start of each symbol [3]. The CP is obtained by taking the last samples of each symbol and consequently the total length of the transmitted OFDM symbols is samples. For each OFDM symbol to be independent and to avoid any Inter Symbol Interference (ISI) or Inter Carrier Interference (ICI) the length of the ....

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computationally complexity algorithms," in Proceedings of IEEE International Conference of Acoustics, Speech and Signal Processing, (Denver), pp. 964--967, April 1980.

....by the propagation channel. In contrast, in CDMA and TDMA systems orthogonal signatures are created in the transmitter at the expense of frequency or time spreading and hence reduced spectral efficiency. Orthogonal Frequency Division Multiplexing. Orthogonal frequency division multiplexing (OFDM) [18, 19, 20, 21] has become part of several telecommunications standards, for example satellite and terrestrial digital audio broadcasting (DAB) digital terrestrial TV broadcasting (DVB) 22] asymmetric digital subscriber line (ADSL) for high bit rate digital subscriber services on twisted pair channels, and ....

....channel impulse response matrix taps H. Note that now H denotes the discrete time channel impulse response obtained by sampling the continuous time impulse response at a rate of where W is the bandwidth of the analog OFDM signal. We assume that the OFDM system W employs a cyclic prefix (CP) [19], which is a copy of the last part of the OFDM symbol prepended to the symbol. The CP acts as a guard space between consecutive OFDM symbols and avoids ISI if the channel impulse response length L is smaller than the length of the CP. Furthermore, if the channel does not change within one OFDM ....

[Article contains additional citation context not shown here]

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," in Proc. IEEE ICASSP-80, (Denver, CO), pp. 964-967, 1980.

....the maximum memory of the transfer and crosstalk coupling functions expressed in number of symbols. Also, the noise samples are white and have (without loss of generality) unit variance. Assuming that all L users are frame synchronized and employ a cyclic prefix of length t (as outlined in [9]) 1) becomes: Yi: Hi,ix1 d Hi,ixi d . d Hi,LXL d Ilti (2) where now xk is a vector of N input symbols of user k, and Hi,i are circulant matrices. Finally, combining all users to gether, 2) becomes: y = Hx n (3) where y = Yl Y . Y] x = IX 1 X 2 . XL] T, n = n n . n] T, ....

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," IEEE ICASSP, Denver, CO, April 1980, pp. 964-967.

....is used for Digital Subscriber Lines. We will address only OFDM systems in this paper. Both schemes use symbols generated by a finite length FFT with size . The orthogonality of the consecutive OFDM symbols is maintained by appending a length cyclic prefix (CP) at the start of each symbol [3]. The CP is obtained by taking the last samples of each symbol and Data Mapper N point IFFT Add CP P S Channel S P Strip CP N point FFT FEQ TEQ Data Demap. AWGN Data In Data Out Fig. 1. Block Diagram of the OFDM System so the total length of the ....

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computationally complexity algorithms," in Proceedings of IEEE International Conference of Acoustics, Speech and Signal Processing, (Denver), pp. 964--967, April 1980.

....the baseband signal and the first image of the D A output signal. The separation results in a significant relaxation of the specification for the image cancelling lowpass filters following the D A. An OFDM transmit block typically consists of the three components shown in Figure 8 (see [12] [18] for example) The original K point block (K=2N=56 in our implementation) a cyclic prefix (extension) and possibly a guard interval. In our realization, a total of 8 samples were allowed for the combination of the cyclic prefix and the guard interval. As will become evident shortly, the ....

A. Peled, A. Ruiz, "Frequency Domain Data Transmission Using Reduced Computational Complexity Algorithms," Proc. IEEE ICASSP `80, pp. 964-967, April 1980.

....scheme and concentrate on the uplink frequency band. In a multiuser mobile environment, an OFDM scheme has two main advantages. First, the receiver does not require an adaptive timedomain equalizer if a cyclic prefix is properly used and if the channel does not change much during one OFDM symbol [10]. Secondly, dynamic channel assignment across the spectrum is straightforward as each user can conveniently access all of the subcarriers by the FFT implemented modulation. Fig. 1 illustrates the OFDM transmission technique. The complex data symbols are coherently modulated on subcarriers by an ....

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," in Proc. IEEE Int. Conf. Acoustics, Speech, Signal Processing, Denver, CO, 1980, pp. 964--967.

....ingress, and impulse noise. In the following, n i is considered to be white and gaussian, and, without loss of generality, has unit variance. Two fundamental assumptions are required in order to proceed: All users must employ block transmission with a CP of at least length (as outlined in [15]) Block transmission and reception at the CO ONU must be synchronized as illustrated in the timing diagram of Fig. 2. Given the co location assumption, synchronized block transmission is relatively straightforward to implement, but synchronized block reception needs some more attention. The ....

....2 : y T L T , x = x T 1 x T 2 : x T L T , n = n T 1 n T 2 : n T L T , and H is a matrix whose (i; j) block is H i;j . The noise covariance matrix is assumed to be R nn = I. Applying the Discrete Fourier Transform (DFT) modulation principle of [18] [15], an Inverse Discrete Fourier Transform (IDFT) operation is performed on each transmitted data block (prior to appending the CP) and a DFT operation is performed on each received data block (after discarding the CP) Y = QmDFT HQ mIDFT X QmDFT n = X N 0 (4) where: Y = Y T 1 Y T 2 : ....

A. Peled and A. Ruiz, \Frequency domain data transmission using reduced computational complexity algorithms, " IEEE ICASSP, Denver, CO, pp. 964-967, Apr. 1980.

No context found.

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computationally complexity algorithms," in Proceedings of IEEE International Conference of Acoustics, Speech and Signal Processing, (Denver), pp. 964--967, April 1980.

No context found.

A. Peled and A. Ruiz. Frequency domain data transmission using reduced computational complexity algorithms. In Proc. IEEE Int. Conf. Acoust., Speech, Signal Processing, pages 964--967, March 1980.

No context found.

A. Peled and A. Ruiz, "Frequency Domain Data Transmission using Reduced Computational Complexity Algorithms," in Int. Conf. on Acoustics, Speech, and Signal Processing, Denver, Colorado, Apr. 1980, pp. 964--967.

No context found.

A. Peled and A. Ruiz. Frequency Domain Data Transmission using Reduced Computational Complexity Algorithms. In Proc. Intern. Conf. on Acoust., Speech and Signal Processing (ICASSP), pages 964-967, Denver, CO, April 1980.

No context found.

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," in Proceedings ICASSP-80 (IEEE International Conference on Acoustics, Speech and Signal Processing), 1980, pp. 964--967.

No context found.

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," in Proceedings ICASSP80 (IEEE International Conference on Acoustics, Speech and Signal Processing), 1980, pp. 964--967.

No context found.

A. Peled and A. Ruiz, "Frequency Domain Data Transmission using Reduced Computational Complexity Algorithms," in Int. Conf. on Acoustics, Speech, and Signal Processing, Denver, Colorado, Apr. 1980, pp. 964--967.

No context found.

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," in Proc. Int. Conf. Acoust., Speech, Signal Processing, ICASSP'80, vol. 3, Denver, CO, Apr. 9--11, 1980, pp. 964--967.

No context found.

A. Peled and A. Ruiz, "Frequency domain data transmission using reduced computational complexity algorithms," in Proc. ICASSP, 1980, pp. 964--967.

First 50 documents

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC