PAPR reduction in FBMC using an ACE-based linear programming optimization

Abstract

This paper presents four novel techniques for peak-to-average power ratio (PAPR) reduction in filter bank multicarrier (FBMC) modulation systems. The approach extends on current PAPR reduction active constellation extension (ACE) methods, as used in orthogonal frequency division multiplexing (OFDM), to an FBMC implementation as the main contribution. The four techniques introduced can be split up into two: linear programming optimization ACE-based techniques and smart gradient-project (SGP) ACE techniques. The linear programming (LP)-based techniques compensate for the symbol overlaps by utilizing a frame-based approach and provide a theoretical upper bound on achievable performance for the overlapping ACE techniques. The overlapping ACE techniques on the other hand can handle symbol by symbol processing. Furthermore, as a result of FBMC properties, the proposed techniques do not require side information transmission. The PAPR performance of the techniques is shown to match, or in some cases improve, on current PAPR techniques for FBMC. Initial analysis of the computational complexity of the SGP techniques indicates that the complexity issues with PAPR reduction in FBMC implementations can be addressed. The out-of-band interference introduced by the techniques is investigated. As a result, it is shown that the interference can be compensated for, whilst still maintaining decent PAPR performance. Additional results are also provided by means of a study of the PAPR reduction of the proposed techniques at a fixed clipping probability. The bit error rate (BER) degradation is investigated to ensure that the trade-off in terms of BER degradation is not too severe. As illustrated by exhaustive simulations, the SGP ACE-based technique proposed are ideal candidates for practical implementation in systems employing the low-complexity polyphase implementation of FBMC modulators. The methods are shown to offer significant PAPR reduction and increase the feasibility of FBMC as a replacement modulation system for OFDM.

Efficiency Analysis of a Truncated Flip-FBMC in Burst Optical Transmission

“…It is noteworthy mentioning that IFFT based AFB is very straightforward to implement, as no extra flipping required as in type-2 Po-De, but in order to emphasize the link and provide better backward compatibility to OFDM, FBMC-TMUX is practically deployed with FFT based AFB [21]- [22]. The bipolar FBMC signal X(k) is obtained by up-sampling ratio of M/2 to compensate the rate loss due to the T/2 of relative time offset for OQAM mapping, followed by combining sub-band signals into one real-filtered signal, and this process called parallel to serial conversion (p/s) [25]. The X(k) signal mutates to unipolar format as () Xk + and () Xk − utilizing flip processing technique, which are juxtaposed in consecutive FBMC-subframes to be employed for IM of the LED, and can be calculated according to [3], [6]…”

Cyclic Shift Based Tone Reservation PAPR Reduction Scheme with Embedding Side Information for FBMC-OQAM Systems

“…After ˆm c being determined, the transmitted data symbols of the mth block can be correctly demodulated according to (22). is the conditional BER with correct SI detection of the proposed scheme.…”

“…To avoid SI transmission, some PAPR reduction methods such as active constellation extension (ACE), clipping and tone reservation (TR) were discussed. The authors in [20][21][22][23] presented an ACE-based method to improve PAPR performance at the cost of increasing the transmitting power. For the clipping method in [24], the BER performance degrades because of signal distortion with hard clipping.…”

Peak to Average Power Ratio Reduction in FBMC Systems by PN-sequences

“…Some of the solutions that were used to reduce PAPR in OFDM systems cannot be applied for FBMC, like Coding, Interleaving, PTS, SML and TI. And this is due to the overlapping between FBMC symbols in the time domain [11].…”

“…Therefore, let M be a frame containing the overlapped FBMC symbols over which the PAPR can be accurately measured. Thus, two different measurements of PAPR can be obtained for the FBMC, the first measurement contains the main all symbols and the second one contains the overlapped symbols frame with length (M -1)N/2 + L, the frame-based PAPR can be defined with s[n] the discrete samples as [11]: Here new symbols 3 are defined, over which the PAPR can be measured. And these symbols are broken up from the modulated signal s[n] to measure the accurate PAPR that be equivalent with the OFDM systems.…”