Analytical approach to I/Q imbalance in OFDM, CDMA and MC-CDMA based systems

Abstract

of lechncl!ogy, set upon communications sensitivity to non-idealities of analog cOllDponenl:s. Mismatches In the and phases branches is one of major concerns iruiuIl�dent rejection of the image frequency band. a novel model of I1Q imbalance in and communicationsAc'cordilll 2 to the obtained results, I1Q imbalance effects heavily on the code class and cell load in case of CDMA and should be taken into account in the system and receiver design. Outcnmes of the theoretical studies are verified by extensive system simnlations.

Orthogonal Complex Hadamard Spreading Codes for I/Q Imbalance Mitigation in MC-CDMA Systems

“…[2], [3], [1], [4]. The analytical model used in this paper was adopted from [1] and modified accordingly. A non-ideal local oscillator is described by:…”

“…Accordingly, the following considerations are based on a MC-CDMA downlink scenario with I/Q imbalance due to non-ideal quadrature demodulation in the receiver. [1] raised the question about the performance of different spreading code sets under I/Q imbalance. This question will be considered here for the MC-CDMA case.…”

Analytical EVM, BER, and TD performances of the OFDM systems in the presence of jointly nonlinear distortion and IQ imbalance

“…Up to now, in the literature, the effects of the nonlinear distortion introduced by HPA and the IQ imbalance of down converter on the performance of the OFDM system have been investigated separately in many papers [4][5][6][7][8][9][10][11][12][13][14]. The effects of IQ imbalances on the OFDM system performance have been discussed in [4][5][6][7][8].…”

“…The effects of IQ imbalances on the OFDM system performance have been discussed in [4][5][6][7][8]. In [4,5], the IQ imbalance effects in OFDM transmission have been investigated by using simulation.…”

“…The impacts of the IQ imbalance of the quadrature down converter on the performance of a Quadrature Phase Shift Keying OFDM system are analytically studied in [6]. Also, an analytical model of IQ imbalance in multicarrier-based communication systems is presented in [7]. However, an analytical expression for the BER is not derived for the OFDM systems.…”