In this letter, a new pulse shaped OFDM-Superposed Quadrature Quadrature Amplitude Modulation (OFDM-SQ2AM) system is proposed to reduce the inter-channel interference (ICI) as well as to maintain the orthogonalities between the OFDM subcarriers in the presence of the subcarrier frequency offset. Time and frequency dispersion properties of the proposed SQ2AM pulse shape are analyzed using the Heisenberg parameter and in-band energy function. Such properties of the proposed pulse are compared with those of a rectangular pulse and IOTA pulse. The BER performance of the pulse shaped OFDM-SQ2AM is compared with those of conventional OFDM-QAM and IOTA/OFDM-OQAM in the 3GPP ITU-R environment. Our simulation results indicate that the proposed OFDM-SQ2AM achieves higher spectral efficiency and power efficiency as compared to the other schemes and gives better robustness of the frequency dispersion.
[1]
Jong Soo Seo,et al.
Performance of Superposed Quadrature Quadrature Amplitude Modulation in Nonlinearly Amplified Multi-Channel Environment(Wireless Communication Technology)
,
2003
.
[2]
Claude Berrou,et al.
Coded orthogonal frequency division multiplex [TV broadcasting]
,
1995,
Proc. IEEE.
[3]
B. Floch,et al.
Coded orthogonal frequency division multiplex
,
1995
.
[4]
Marc Moeneclaey,et al.
BER sensitivity of OFDM systems to carrier frequency offset and Wiener phase noise
,
1995,
IEEE Trans. Commun..
[5]
Jong-Soo Seo,et al.
SQAM: A New Superposed QAM Modem Technique
,
1985,
IEEE Trans. Commun..
[6]
Pierre Siohan,et al.
Cosine-modulated filterbanks based on extended Gaussian functions
,
2000,
IEEE Trans. Signal Process..