Sensitivity of OFDM-CDMA Systems to Carrier Frequency Offset

Nasser, Youssef; Noes, Mathieu Des; Ros, Laurent; Jourdain, Geneviève

doi:10.1109/icc.2006.255361

Cited by 12 publications

(9 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Neglecting the SFO effects which are much less significant than CFO [5], the received symbol in the presence of CFO during the qth OFDM symbol on the n′th subcarrier of the subset of subcarriers (t, s′) corresponding to a component of vector zt,s′ in equation (3) expresses as follows: (15) where ϕ(s′, s, n′, n) is an equivalent transfer function describing the attenuation and the phase rotation caused by the CFO. It is equal to: (16) where ψ N (x) is the Dirichlet function defined by: . The second term in (15) is the ICI coming from the other active subcarriers in the same OFDM symbol.…”

Section: A New Waveform Based On Linear Precoded Multicarrier Modulatmentioning

confidence: 99%

“…In our study, we assumed that these interferences have Gaussian distribution with zero mean [15] [16]. Consequently, if the product S × Lf × (Lt − 1) is large enough: (20) Using (18) and (20), it is straightforward to say that the CFO is the measure of the phase of t (ζ): (21) It should be noted that to avoid any phase ambiguity, it is necessary that: (22) This constraint determinates the maximum estimable CFO value at this stage.…”

Section: A New Waveform Based On Linear Precoded Multicarrier Modulatmentioning

confidence: 99%

See 1 more Smart Citation

A New Waveform based on Linear Precoded Multicarrier Modulation for Future Digital Video Broadcasting Systems

Pasquero¹,

Crussière²,

Youssef³

et al. 2010

Digital Video

Self Cite

View full text Add to dashboard Cite

Section: A New Waveform Based On Linear Precoded Multicarrier Modulatmentioning

confidence: 99%

Section: A New Waveform Based On Linear Precoded Multicarrier Modulatmentioning

confidence: 99%

A New Waveform based on Linear Precoded Multicarrier Modulation for Future Digital Video Broadcasting Systems

Pasquero¹,

Crussière²,

Youssef³

et al. 2010

Digital Video

Self Cite

View full text Add to dashboard Cite

“…In [8], the BER performance of multiple antenna OFCDM systems with imperfections was studied. In [9], the sensitivity of OFDM-CDMA systems to carrier frequency offset was investigated for zero forcing and minimum mean square error equalizers. However, no subcarrier grouping was considered in their analysis, although the subcarrier grouping strategy has an impact on the different types and amount of interference introduced with frequency offset.…”

Section: Introductionmentioning

confidence: 99%

Carrier Frequency Offset in VSF-OFCDM Systems with Subcarrier Grouping: Analysis, Estimation and Correction

Khalid

Anpalagan

2010

Wireless Pers Commun

View full text Add to dashboard Cite

We investigate the effect of carrier frequency offset (CFO) on the performance of downlink variable spreading factor (VSF) orthogonal frequency and code division multiple access (OFCDM) systems when subcarrier grouping is used. An analytic expression of the signal to interference and noise ratio (SINR) is derived for the VSF-OFCDM with CFO for the case of maximal ratio combining (MRC) and equal gain combining (EGC) receivers. Numerical results show that, when the total spreading factor is fixed, a system with higher frequency domain spreading factor is more sensitive to CFO than that with lower frequency domain spreading factor. Also, for high E b /N o , EGC has better bit error rate performance than MRC due to the greater interference amplification present in MRC which compounds the effect of the loss of orthogonality. Due to the adverse impact of the CFO on VSF-OFCDM systems, we propose a correction scheme based on the maximum likelihood principle. We then use a gradient algorithm to estimate and minimize the effect of CFO in a tracking mode. Our results show that the BER performance in the low SINR environment can be improved significantly with few number of iterations for different spreading factors.

show abstract

“…In the literature, several works could be found on the CFO effects in the mutli-carrier based systems [3][4] [5].…”

Section: Introductionmentioning

confidence: 99%

On the system level prediction of joint time frequency spreading systems with carrier phase noise

Nasser

Noes

Ros

et al. 2010

IEEE Trans. Commun.

Self Cite

View full text Add to dashboard Cite

Abstract---Phase noise is a topic of theoretical and practical interest in electronic circuits. Although progress has been made in the characterization of its description, there are still considerable gaps in its effects especially on multi-carrier spreading systems. In this paper, we investigate the impact of a local oscillator phase noise on the multi-carrier 2 dimensional (2D) spreading systems based on a combination of orthogonal frequency division multiplexing (OFDM) and code division multiple access (CDMA) and known as OFDM-CDMA. The contribution of this paper is multifold. First, we use some properties of random matrix and free probability theory to give a simplified expression of signal to interference and noise ratio (SINR) obtained after equalization and despreading. This expression is independent of the actual value of the spreading codes and depends mainly on the complex amplitudes of estimated channel coefficients. Secondly, we use this expression to derive new weighting functions which are very interesting for the radio frequency (RF) engineers when they design the frequency synthesizer. Therefore, based on these asymptotic results, we adapt a new method to predict the bit error rate (BER) at the output of the channel decoder by using an effective SINR value. We show by simulations the validity of our models and that at a given BER, the required signal to noise ratio (SNR) may easily increase due to the carrier phase noise.Index Terms---Multi-carrier spreading systems, large system analysis, phase noise, SINR, EESM.

show abstract

Sensitivity of OFDM-CDMA Systems to Carrier Frequency Offset

Cited by 12 publications

References 19 publications

A New Waveform based on Linear Precoded Multicarrier Modulation for Future Digital Video Broadcasting Systems

A New Waveform based on Linear Precoded Multicarrier Modulation for Future Digital Video Broadcasting Systems

Carrier Frequency Offset in VSF-OFCDM Systems with Subcarrier Grouping: Analysis, Estimation and Correction

On the system level prediction of joint time frequency spreading systems with carrier phase noise

Contact Info

Product

Resources

About