BER sensitivity of OFDM systems to carrier frequency offset and Wiener phase noise
TL;DR: In this contribution the transmission of M-PSK and M-QAM modulated orthogonal frequency division multiplexed (OFDM) signals over an additive white Gaussian noise (AWGN) channel is considered and the degradation of the bit error rate is evaluated.
Abstract: In this contribution the transmission of M-PSK and M-QAM modulated orthogonal frequency division multiplexed (OFDM) signals over an additive white Gaussian noise (AWGN) channel is considered. The degradation of the bit error rate (BER), caused by the presence of carrier frequency offset and carrier phase noise is analytically evaluated. It is shown that for a given BER degradation, the values of the frequency offset and the linewidth of the carrier generator that are allowed for OFDM are orders of magnitude smaller than for single carrier systems carrying the same bit rate. >
Citations
More filters
TL;DR: A rapid synchronization method is presented for an orthogonal frequency-division multiplexing (OFDM) system using either a continuous transmission or a burst operation over a frequency-selective channel.
Abstract: A rapid synchronization method is presented for an orthogonal frequency-division multiplexing (OFDM) system using either a continuous transmission or a burst operation over a frequency-selective channel. The presence of a signal can be detected upon the receipt of just one training sequence of two symbols. The start of the frame and the beginning of the symbol can be found, and carrier frequency offsets of many subchannels spacings can be corrected. The algorithms operate near the Cramer-Rao lower bound for the variance of the frequency offset estimate, and the inherent averaging over many subcarriers allows acquisition at very low signal-to-noise ratios (SNRs).
3,492 citations
Cites background from "BER sensitivity of OFDM systems to ..."
...spacing between the subcarriers without a large degradation in system performance [1]....
[...]
TL;DR: This article surveys frequency domain equalization (FDE) applied to single-carrier (SC) modulation solutions and discusses similarities and differences of SC and OFDM systems and coexistence possibilities, and presents examples of SC-FDE performance capabilities.
Abstract: Broadband wireless access systems deployed in residential and business environments are likely to face hostile radio propagation environments, with multipath delay spread extending over tens or hundreds of bit intervals. Orthogonal frequency-division multiplex (OFDM) is a recognized multicarrier solution to combat the effects of such multipath conditions. This article surveys frequency domain equalization (FDE) applied to single-carrier (SC) modulation solutions. SC radio modems with frequency domain equalization have similar performance, efficiency, and low signal processing complexity advantages as OFDM, and in addition are less sensitive than OFDM to RF impairments such as power amplifier nonlinearities. We discuss similarities and differences of SC and OFDM systems and coexistence possibilities, and present examples of SC-FDE performance capabilities.
2,475 citations
TL;DR: In this paper, the joint maximum likelihood (ML) symbol-time and carrier-frequency offset estimator is presented for orthogonal frequency-division multiplexing (OFDM) systems.
Abstract: We present the joint maximum likelihood (ML) symbol-time and carrier-frequency offset estimator in orthogonal frequency-division multiplexing (OFDM) systems. Redundant information contained within the cyclic prefix enables this estimation without additional pilots. Simulations show that the frequency estimator may be used in a tracking mode and the time estimator in an acquisition mode.
2,232 citations
TL;DR: In this paper, the authors give a tutorial overview of OFDM and highlight the aspects that are likely to be important in optical applications, and discuss the constraints imposed by single mode optical fiber, multimode optical fiber and optical wireless.
Abstract: Orthogonal frequency division multiplexing (OFDM) is a modulation technique which is now used in most new and emerging broadband wired and wireless communication systems because it is an effective solution to intersymbol interference caused by a dispersive channel. Very recently a number of researchers have shown that OFDM is also a promising technology for optical communications. This paper gives a tutorial overview of OFDM highlighting the aspects that are likely to be important in optical applications. To achieve good performance in optical systems OFDM must be adapted in various ways. The constraints imposed by single mode optical fiber, multimode optical fiber and optical wireless are discussed and the new forms of optical OFDM which have been developed are outlined. The main drawbacks of OFDM are its high peak to average power ratio and its sensitivity to phase noise and frequency offset. The impairments that these cause are described and their implications for optical systems discussed.
1,761 citations
TL;DR: The inner OFDM receiver and its functions necessary to demodulate the received signal and deliver soft information to the outer receiver for decoding are focused on.
Abstract: Orthogonal frequency-division multiplexing (OFDM) is the technique of choice in digital broad-band applications that must cope with highly dispersive transmission media at low receiver implementation cost. In this paper, we focus on the inner OFDM receiver and its functions necessary to demodulate the received signal and deliver soft information to the outer receiver for decoding. The effects of relevant nonideal transmission conditions are thoroughly analyzed: imperfect channel estimation, symbol frame offset, carrier and sampling clock frequency offset, time-selective fading, and critical analog components. Through an appropriate optimization criterion (signal-to-noise ratio loss), minimum requirements on each receiver synchronization function are systematically derived. An equivalent signal model encompassing the effects of all relevant imperfections is then formulated in a generalized framework. The paper concludes with an outline of synchronization strategies.
891 citations
Cites background from "BER sensitivity of OFDM systems to ..."
...There are two consequences for the received OFDM signal which may result from a poor phase noise spectrum [24], [25]....
[...]
References
More filters
TL;DR: The general technique of parallel transmission on many carriers, called multicarrier modulation (MCM), is explained, and the performance that can be achieved on an undistorted channel and algorithms for achieving that performance are discussed.
Abstract: The general technique of parallel transmission on many carriers, called multicarrier modulation (MCM), is explained. The performance that can be achieved on an undistorted channel and algorithms for achieving that performance are discussed. Ways of dealing with channel impairments and of improving the performance through coding are described, and implementation methods are considered. Duplex operation of MCM and the possible use of this on the general switched telephone network are examined. >
3,995 citations
TL;DR: A discrete multitone (DMT) transceiver design for high bit rate digital subscriber line (HDSL) access is presented and analyzed and is an excellent candidate for HDSL implementation.
Abstract: A discrete multitone (DMT) transceiver design for high bit rate digital subscriber line (HDSL) access is presented and analyzed. The DMT transmitter and receiver structure and algorithms are detailed, and the computational requirements of DMT for HDSL are estimated. At a sampling rate of 640 kHz, using an appropriate combination of a short finite-impulse-response (FIR) equalizer and a length-512 DMT system, 1.6 Mb/s data transmission is possible within the carrier serving area (CSA) at an error rate of 10/sup -7/ on a single twisted pair. A significant performance margin can be achieved when two coordinated twisted pairs are used to deliver a total data rate of 1.6 Mb/s. In terms of a performance-per-computation figure of merit, the DMT system is an excellent candidate for HDSL implementation. >
549 citations
02 Dec 1991
TL;DR: A static code design with unequal error protection (UEP) is presented that also takes auxiliary data services into account and emphasis is on the use of source-adapted channel coding with rate-compatible punctured convolutional (RCPC) codes.
Abstract: A system proposal for DAB is investigated. The kernel is orthogonal frequency division multiplexing (OFDM) with 4-DPSK (differential phase shift keying) modulation, rectangular pulse-shaping, and a guard interval to reject multipath distortions. Emphasis is on the use of source-adapted channel coding with rate-compatible punctured convolutional (RCPC) codes. Based on analytical and simulated BER (bit error rate) curves for several propagation conditions and on preliminary source significance information (SSI), a static code design with unequal error protection (UEP) is presented that also takes auxiliary data services into account. The gain due to UEP is on the order of 8dB in signal power or 25% in bandwidth. >
69 citations
TL;DR: By means of theoretical analysis, it is demonstrated that even simple interpolators, operating at only a few samples per symbol, yield BER degradations that are limited to a small fraction of a dB.
Abstract: This paper deals with the bit error rate (BER) performance of a fully digitally implemented receiver performing coherent detection on a narrowband BPSK or (O)QPSK signal, transmitted over a slow non-frequency selective Rician fading channel. The considered digital receiver operates on samples of the received signal, taken by a fixed clock which is not synchronized to the transmitter clock. Signal samples needed for detection of the information sequence are obtained from interpolation between the available samples. In the case of nonideal interpolation a BER degradation occurs. By means of theoretical analysis, we demonstrate that even simple interpolators, operating at only a few samples per symbol, yield BER degradations that are limited to a small fraction of a dB. This paper is an extension of the work of Erup, Gardner and Harris (see ibid., vol.41, no.6, p.998-1008, 1993) where only the AWGN channel was considered and results were obtained by computer simulations. >
22 citations
TL;DR: This contribution deals with the digital broadcasting of HDTV channels over the cable television (CATV) distribution system, using either single-carrier QAM or an orthogonal frequency division multiplex of many QAM carriers to represent an HDTV channel.
Abstract: This contribution deals with the digital broadcasting of HDTV channels over the cable television (CATV) distribution system, using either single-carrier QAM or an orthogonal frequency division multiplex (OFDM) of many QAM carriers to represent an HDTV channel. Assuming that no error-correcting codes are used, we investigate two distinct cases: in the first case, a few HDTV channels are transmitted among many analog TV channels, whereas in the second case all transmitted channels are HDTV channels. We show that in the first case the transmit power of an HDTV channel can be substantially reduced (by about 10 dB or more) as compared to the transmit power of an analog TV channel, while still maintaining a satisfactory bit error rate (BER). In the second case, not only a considerable reduction of the total transmit power but also a reduction of amplifier cost and an increase of the number of TV channels can be achieved. Single-carrier QAM is found to perform slightly better (at most about 1 or 2 dB) than a multi-carrier QAM.
12 citations