Capacity Maximizing ICI Canceling Windows for OFDM in Time-Varying Channels

Abstract

Abstract-The rate-t/k (t ≤ k) OFDM systems with the intercarrier interference (ICI) canceling windows are presented by generalizing the existing rate-1/k system and the capacity lower bounds of these systems for timevarying frequency selective channels are analyzed. Based on the capacity analysis, the optimal windows maximizing the capacity lower bounds are designed numerically with an assumption that the channel is flat fading. The effects of ICI canceling windows on the capacity lower bounds are examined through numerical simulations and the results indicate that considerable performance improvement can be achieved by employing the proposed windows, as compared with the conventional systems with/without windowing when the channel varies very rapidly.

Channel capacity of OFDM systems employing diversity in fading environments

“…A moment generating function approach was recently proposed in Reference 6 as a new and effective method to study channel capacity. Research work on OFDM channel capacity has been scarce for cancelled ICI with some findings reported in Reference 7. However, the effectiveness of MRC and SC diversities was not considered in Reference 7.…”

“…Research work on OFDM channel capacity has been scarce for cancelled ICI with some findings reported in Reference 7. However, the effectiveness of MRC and SC diversities was not considered in Reference 7.…”

Adaptive orthogonal frequency division multiplexing channel capacity employing diversity in cellular fading environments with symmetric scattering distributions

“…It is clear that the analytical expression for the P ICI given in (7) is difficult to obtain. However, under specific conditions, (7) can be simplified to a simpler form, which can be helpful for ICI analysis.…”

“…It is clear that the analytical expression for the P ICI given in (7) is difficult to obtain. However, under specific conditions, (7) can be simplified to a simpler form, which can be helpful for ICI analysis. Inserting (1) and (2) to (7), the Gaussian and hyperbolic P ICI can be given as functions of and  as From (1) and (2), for microcell wireless communications, that is, is sufficiently small, then the Gaussian and hyperbolic channels can be approximated as having a single bell-shaped term, the Gaussian and hyperbolic ICI given in (8) and (9) can be rewritten as…”

“…If the P ICI difference is positive, it can be said that the Gaussian AoA pdf is less effective than the hyperbolic AoA pdf and vice versa. From (7), it is clear that the P ICI is dependent on the AoA pdf, which is also dependent on . For different AoA pdfs given in (1) and (2), different values of P ICI can be obtained.…”