# Bit Error Rate Analysis Of Ofdm/tdm With Frequency-domain Equalization

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Thus, the BER for the th frame is obtained as , while the average BER is obtained by [1] (11) where denotes the normalized covariance given by Transactions (1976-1990) Volume List[JPN Edition] A JPN Edition(in Japanese) B JPN Edition(in Japanese) C JPN Edition(in Japanese) D JPN Edition(in Japanese) - Editorial Board Editorial Board Trans.Fundamentals. Then, the -point FFT is applied to obtain the improved channel gain estimates given by (7) for , where and , respectively, denote the distorted check my blog

Thus, the nonlinear noise **due to the quantization** and HPA amplitude saturation is spread over data subcarriers after the interpolation. ConclusionsAppendix Declarations ReferencesComments Metrics Share this article Share on Twitter Share on Facebook Share on LinkedIn Share on Weibo Share on Google Plus Share on Reddit Other Actions Order reprint Advertisement JPN Edition(in Japanese) B Communications Trans.Commun. Electron.

Trans. Please try the request again. Summary Japanese Page SITE TOP Login To browse Full-Text PDF. > Forgotten your password? Naturally, this will have a negative effect on the channel estimator's performance in comparison with the pilot-assisted CE using the TDM pilot. 5.

Trans.Commun. Subscribe Enter Search Term First Name / Given Name Family Name / Last Name / Surname Publication Title Volume Issue Start Page Search Basic Search Author Search Publication Search Advanced Search It is evident that the quantization noise represented through quantization step affects more the MSE of the channel estimator for the FDM-based pilot-assisted CE. ICCS 2004.

The analysis is based on a Gaussian approximation of the nonlinear noise due to both HPA amplitude limitation and quantization. IEEE Transactions on Communications 2001, 49(8):1375-1387. 10.1109/26.939860View ArticleMATHGoogle ScholarSchmidt H, Kammeyer K-D: Quantization and its effects on OFDM concepts for wireless indoor applications. To further improve the bit error rate (BER) performance of conventional OFDM an interleaving technique may be applied, but FDE cannot be fully exploited. Thus, in this paper we refer to amplitude clipping as the amplitude saturation of the HPA.

Usually, DA and AD converters are assumed to have a large number of quantization levels and an optimally exploited dynamic range. Part **of Springer** Nature. AppendixHere, we present a derivation of the second moments of the random variables and given by , , and . (1) TDM pilotUsing (4) the second IEEE Transactions on Wireless Communications 2010, 9(11):3472-3479.View ArticleGoogle ScholarRyu HG, Hoa TP, Hieu NT, Jianxue J: BER analysis of clipping process in the forward link of the OFDM-FDMA communication system.

Various CE schemes have been proposed for OFDM [2–5], where the pilot signals are multiplexed either in the time (TDM pilot) or in the frequency domain (FDM pilot). We note here that the propagation error effect is captured in (13) by the coefficient . Here, , and denote the second moments of the random variables , , and , respectively. We emphasize here that the case of and represents a linear HPA and an ideal quantizer.Table 1 Numerical parameters.

The OFDM signal is fed to a DA converter to transform the signal from the digital to the analog domain. click site On the other hand, the CE **with an FDM pilot** improves the tracking against a fast fading, but the performance degrades, since the noise is spread over all subcarriers due to Mathematical Signal Representation The th ( ) frame of the data-modulated symbols with is transmitted during one signaling interval. We emphasize that we introduce the clipping effect through an HPA, for which the input-output soft-limiter characteristic is approximated by (2).

System Model3. Ideal CE For the ideal CE, we have , and consequently, using (4), the random variables and are given by (20) Then, , , and FDM Pilot CE with the FDM pilot requires a frequency interpolation. news However, in a real implementation, in order to keep the system complexity and the power consumption low, it is desirable to keep the resolution of the DA/AD converters as low as

Please try the request again. IEEE Communications Magazine 1997, 35(12):126-144. 10.1109/35.642841View ArticleGoogle ScholarChu DC: Polyphase codes with good periodic correlation properties. IEEE Transactions on Broadcasting 2002, 48(3):223-229. 10.1109/TBC.2002.804034View ArticleGoogle ScholarHsieh MH, Wei CH: Channel estimation for OFDM systems based on comb-type pilot arrangement in frequency selective fading channels.

## We have chosen for the normalized Doppler frequency (where ), which corresponds to a terminal speed of 40 km/h for a 2 GHz carrier frequency and a transmission data rate of

Moreover, the frequency-domain interpolation will cause **spreading of the nonlinear noise** over all the subcarriers leading to a larger BER performance degradation in comparison with CE using the TDM pilot. Trans.Commun. We note that the relation between and the input backoff is given as , where denotes the average input power. Introduction2.

In [22], it was shown that the optimum FDM-pilot scheme is the one with equally spaced inserted pilots. Try again later.Show moreDates and citation counts are estimated and are determined automatically by a computer program.Help Privacy Terms Provide feedback Get my own profile ERROR The requested URL could not We assume that the data rate is kept the same for both the TDM and FDM pilot schemes since an equal number of pilot subcarriers is transmitted within the transmission block More about the author Unlike previous papers, where nonlinear noise due to the HPA and the quantization is treated separately, we take into consideration the effects of both.

This is because of the fact that for pilot-assisted CE using the FDM pilot, the pilot signals are inserted onto dedicated (i.e., pilot) subcarriers in frequency domain within the OFDM signal. It is shown in [17] that for the amplitude saturation level dB, . JPN Edition(in Japanese) Abstracts of JPN Edition Trans.Fundamentals. Naturally, this will have a negative effect on the FDM pilot performance in comparison with TDM pilot.

Generated Sun, 02 Oct 2016 13:27:24 GMT by s_hv996 (squid/3.5.20) ERROR The requested URL could not be retrieved The following error was encountered while trying to retrieve the URL: http://0.0.0.8/ Connection Hence, an interpolation is required to obtain the channel gains for all frequencies (i.e., ). Assuming that the channel impulse response is present only within the GI, the estimated channel impulse response beyond the GI is replaced with zeros to reduce the noise [21], and an Your cache administrator is webmaster.

In a fading channel, the performance of an OFDM system with CE using a TDM pilot gets rapidly degraded whenever the channel has a significant time variance. Please try the request again. IEEE Transactions on Communications 1998, 46(7):931-939. 10.1109/26.701321View ArticleGoogle ScholarNegi R, Cioffi J: Pilot tone selection for channel estimation in a mobile ofdm system.