Iterative Interference Cancellation for Coded Filter Bank Multicarrier Systems

2019 ◽  
Vol 10 (4) ◽  
pp. 81-93
Author(s):  
Mohammad Razk Assaf ◽  
Abdel-Nasser Assimi
Keyword(s):  
Interference Cancellation ◽  
Communication Systems ◽  
Filter Bank ◽  
Signal To Noise Ratio ◽  
Minimum Mean Square Error ◽  
Turbo Equalization ◽  
International Telecommunication Union ◽  
Filter Bank Multicarrier ◽  
Processing Delay ◽  
Iterative Interference Cancellation

Filter bank multicarrier is one of the candidates for future communication systems. Simple equalization methods cannot be directly applied due to the high interference from adjacent channels. In this article, the authors derive a soft-input/soft-output (SISO) equalizer based on the minimum mean square error (MMSE) criterion for the bit-interleaved coded system using a filter bank multi-carrier scheme with offset quadrature amplitude modulation (FBMC/OQAM). The authors use this SISO-MMSE equalizer in a turbo-equalization scheme for each sub-carrier. The difficulty in this implementation comes from the required processing delay per turbo-iteration due to the non-causal nature of the interference in this system. Therefore, the number of turbo-iterations is limited in order to limit the processing delay. The authors evaluate the performance of the proposed turbo-equalizer over the International Telecommunication Union (ITU) Vehicular B channel by mean of numerical simulations. The obtained results show the effectiveness of the proposed equalizer in term of signal-to-noise ratio (SNR) gain.

scholarly journals Iterative Interference Cancellation for Multi-Carrier Modulation in MIMO-DWT Downlink Transmission

2021 ◽  
Vol 9 (4) ◽  
pp. 75-87
Author(s):  
Yahya Harbi ◽  
ALI AL-JANABI ◽  
Hayder Almusa ◽  
Marwa Chafii ◽  
Alister Burr
Keyword(s):  
Interference Cancellation ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Minimum Mean Square Error ◽  
Multiple Input Multiple Output ◽  
Multipath Channel ◽  
Discrete Wavelet ◽  
Ldpc Decoder ◽  
Mimo Ofdm ◽  
Iterative Interference Cancellation

The Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) scheme represents the dominant radio interface for broadband multicarrier communication systems. However, with insufficient Cyclic Prefixes (CP), Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI) occur due to the time-varying multipath channel. This means that the performance of the system will be degraded. In this paper, we investigate the interference problem for a MIMO Discrete Wavelet Transform (MIMO-DWT) system under the effect of the downlink LTE channel. A Low-Density Parity-Check (LDPC) decoder is used to estimate the decoded signal. The proposed iterative algorithm uses the estimated decoded signal to compute the components required for ICI/ISI interference reduction. In this paper, Iterative Interference Cancellation (IIC) is employed to mitigate the effects of interference that contaminates the received signal due to multiple antenna transmission and a multipath channel. An equalizer with minimum mean square error is considered. We compare the performance of our proposed algorithm with the traditional MIMO-OFDM scheme in terms of bit error probability under insufficient CP. Simulation results verify that significant improvements are achieved by using IIC and MIMO-IIC for both systems.

scholarly journals Análisis de la técnica UFMC en un canal multitrayecto y usando estimación de canal

2021 ◽  
Vol 9 (17) ◽  
pp. 26-39
Author(s):  
Hugo Wladimir Iza Benítez ◽  
Diego Javier Reinoso Chisaguano
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Filter Bank ◽  
Estimation Method ◽  
Wireless Communication Systems ◽  
Ofdm Systems ◽  
Matlab Simulation ◽  
Fifth Generation ◽  
Power Spectral ◽  
Filter Bank Multicarrier

UFMC (Universal Filtered Multi-Carrier) is a novel multi-carrier transmission technique that aims to replace the OFDM (Orthogonal Frequency Division Multiplexing) modulation technique for fifth generation (5G) wireless communication systems. UFMC, being a generalization of OFDM and FBMC (Filter Bank Multicarrier), combines the advantages of these systems and at the same time avoids their main disadvantages. Using a Matlab simulation, this article presents an analysis of the robustness of UFMC against fading effects of multipath channels without using a CP (cyclic prefix). The behavior of the UFMC system is analyzed in terms of the PSD (Power Spectral Density), BER (Bit Error Rate) and MSE (Mean Square Error). The results show that UFMC reduces the out-band side lobes produced in the PSD of the processed signal. Also, it is shown that the pilot-assisted channel estimation method applied in OFDM systems can also be applied in UFMC systems.

scholarly journals A Hybrid PAPR Reduction Method Based on SLM and Multi-Data Block PTS for FBMC/OQAM Systems

Information ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 246 ◽  
Author(s):  
Han Wang
Keyword(s):  
Communication Systems ◽  
Filter Bank ◽  
Reduction Method ◽  
Average Power ◽  
Data Block ◽  
Papr Reduction ◽  
Wireless Communication Systems ◽  
Transmission Scheme ◽  
Filter Bank Multicarrier ◽  
Selective Mapping

The filter bank multicarrier employing offset quadrature amplitude modulation (FBMC/OQAM) is a candidate transmission scheme for 5G wireless communication systems. However, it has a high peak-to-average power ratio (PAPR). Due to the nature of overlapped signal structure of FBMC/OQAM, conventional PAPR reduction schemes cannot work effectively. A hybrid PAPR reduction scheme based on selective mapping (SLM) and multi data block partial transmit sequence (M-PTS) methods is proposed for FBMC/OQAM signals in this paper. Different from the simple SLM-PTS method, the proposed hybrid algorithm takes into account the overlapping effect of multiple adjacent data blocks on its PTS process. From simulation results, it can be obtained that the proposed method can offer a significant PAPR reduction performance improvement compared with the SLM, PTS and SLM-PTS methods. The proposed method can effectively reduce the PAPR in FBMC/OQAM systems.

PERFORMANCE ANALYSIS OF MULTIPLE ACCESS CHAOTIC-SEQUENCE SPREAD-SPECTRUM COMMUNICATION SYSTEMS USING PARALLEL INTERFERENCE CANCELLATION RECEIVERS

2004 ◽  
Vol 14 (10) ◽  
pp. 3633-3646 ◽  
Author(s):  
WAI M. TAM ◽  
FRANCIS C. M. LAU ◽  
CHI K. TSE
Keyword(s):  
Spread Spectrum ◽  
Interference Cancellation ◽  
Communication Systems ◽  
Multiple Access ◽  
Minimum Mean Square Error ◽  
Chaotic Sequence ◽  
Spread Spectrum Communication ◽  
Parallel Interference Cancellation ◽  
Decorrelating Detector ◽  
Error Detector

In this Letter, we apply combined linear detector/parallel interference cancellation (PIC) detectors to jointly decode symbols in a multiple access chaotic-sequence spread-spectrum communication system. In particular, three different types of linear detectors, namely single-user detector, decorrelating detector and minimum mean-square-error detector, are used to estimate the transmitted symbols at the first stage of the PIC detector. The technique for deriving the approximate bit error rate (BER) is described and computer simulations are performed to verify the analytical BERs.

scholarly journals CLIPPING TECHNIQUES FOR PAPR REDUCTION IN FBMC/OQAM SYSTEM OVER DOUBLY-SELECTIVE CHANNELS

2021 ◽  
Vol 25 (5) ◽  
pp. 85-94
Author(s):  
Noor Q. Lateef ◽  
◽  
Fadhil S. Hasan ◽  
Keyword(s):  
Communication Systems ◽  
Filter Bank ◽  
Average Power ◽  
High Peak ◽  
Papr Reduction ◽  
Doubly Selective Channels ◽  
Matlab Program ◽  
Filter Bank Multicarrier ◽  
Nonlinear Power Amplifier ◽  
Reduction Methods

One of the major disadvantages of Filter Bank Multicarrier (FBMC) is high Peak-to-Average Power Ratio (PAPR) of transmitted signal. As a result, nonlinear power amplifier (PA) properties, considerable out-of-band and the in-band distortion types take place in the case where the signals of high peak exceed the PA saturation level. In the present study, a new method of the PAPR reduction is presented and applied to reduce PAPR in FBMC/OQAM system. Different clipping methods have been proposed and studied that are Amplitude Clipping (AC), Palm Clipping (PC), Deep Clipping (DC), and smooth Clipping (SC) for the reduction of PAPR. To evaluate and analyze the performance of PAPR reduction methods, PAPR and Bit Error Rate (BER) measures are used and programmed using MATLAB program. The simulation results show that the clipping methods are strong substitute methods which may be assumed as a method of PAPR reduction for the FBMC-based communication systems and AC appears to be the best method.

scholarly journals An Efficient Turbo Decoding and Frequency Domain Turbo Equalization for LTE Based Narrowband Internet of Things (NB-IoT) Systems

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5351
Author(s):  
Mohammed Jajere Adamu ◽  
Li Qiang ◽  
Rabiu Sale Zakariyya ◽  
Charles Okanda Nyatega ◽  
Halima Bello Kawuwa ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Turbo Codes ◽  
Channel Coding ◽  
Interference Cancellation ◽  
Minimum Mean Square Error ◽  
Turbo Equalization ◽  
Posteriori Probability ◽  
Turbo Decoding ◽  
A Posteriori Probability ◽  
Phy Layer

This paper addresses the main crucial aspects of physical (PHY) layer channel coding in uplink NB-IoT systems. In uplink NB-IoT systems, various channel coding algorithms are deployed due to the nature of the adopted Long-Term Evolution (LTE) channel coding which presents a great challenge at the expense of high decoding complexity, power consumption, error floor phenomena, while experiencing performance degradation for short block lengths. For this reason, such a design considerably increases the overall system complexity, which is difficult to implement. Therefore, the existing LTE turbo codes are not recommended in NB-IoT systems and, hence, new channel coding algorithms need to be employed for LPWA specifications. First, LTE-based turbo decoding and frequency-domain turbo equalization algorithms are proposed, modifying the simplified maximum a posteriori probability (MAP) decoder and minimum mean square error (MMSE) Turbo equalization algorithms were appended to different Narrowband Physical Uplink Shared Channel (NPUSCH) subcarriers for interference cancellation. These proposed methods aim to minimize the complexity of realizing the traditional MAP turbo decoder and MMSE estimators in the newly NB-IoT PHY layer features. We compare the system performance in terms of block error rate (BLER) and computational complexity.

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