Flexible Implementation of Multicarrier Systems with Polyphase Filterbanks

Abstract

Abstract. This article will emphasize on how to efficiently implement multicamer (MC-) systems different from and alternative to OFDM with polyphase filterbanks. It will show that when using polyphase filterbanks this is an incomplex and flexible solution. It will be derived that with polyphase filterbanks an additional MC-system design parameter exists; not only spacings between adjacent subcarriers in integer multiples of the inverse MC-symbol duration are possible but that also non-integer multiples of the inverse MC-symbol duration are easily realizable.

Evaluation of Clipping Based Iterative PAPR Reduction Techniques for FBMC Systems

“…Throughout this paper the prototype filter described in [ 21 ] is applied with an overlapping factor of K = 4. Equation ( 1 ) can be implemented in a computationally efficient way using IFFT and a polyphase decomposition of the modulated prototype filters, with the two output signals being time staggered and added as presented in [ 22 , 23 ].…”

Systematic design of transmitter and receiver architectures for flexible filter bank multi-carrier signals

“…It is important to mention that the matching network module in Figure 7 usually requires interpolation operations by a factor Q, which can be easily accommodated as long as Q is an integer number. The implementation for rational values of Q becomes challenging and it can be shown that the role of these interpolation modules would lead to timevariant input-output responses of the polyphase network when conventional methods are used [14,33,34]. In this work though, we show that it is possible to obtain efficient and time-invariant architectures for any value of Q, thus enabling a much simpler and cheaper implementation of FBMC user and network terminals.…”

“…= g[ kP to N ss + mod(m r , P to N ss )]. We can see that there appears again a shift of l r N ss samples in (33) at the subscripts of the prototype filter with respect to the IDFT output subscript. Following an analogous reasoning to subsection 4.2.1), we can write…”

“…For these reasons, the implementation issues of this type of MC signals have been ignored in the literature or solved by means of time-variant schemes [33,34]. In spite of these obstacles, we show in this work that if the polyphase and matching networks are properly designed, it is certainly possible to obtain a time-invariant structure for any rational value of Q.…”

“…Typically, most works such as [21] and [32] do not consider all possible FBMC signals but only a small subset thereof, where simple implementations can easily be derived [27]. Other works like [14,33,34] do address those intricate cases, but the resulting architectures entail time-varying filtering coefficients, which require an unnecessary complex control and operation of memory buffers. The authors in [35] have come up with efficient architectures for some of theses intricate cases, but the overall process is specifically tailored to these signals, thus lacking a systematic derivation and general applicability in practice.…”