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.

Research for Parameter Estimation of Linear Frequency Modulation Signals

2014 ◽  
Vol 602-605 ◽  
pp. 3698-3701
Author(s):  
Hai Sheng Liu ◽  
Cang Chen
Keyword(s):  
Maximum Likelihood ◽  
Maximum Likelihood Estimate ◽  
Minimum Mean Square Error ◽  
Likelihood Estimate ◽  
Posteriori Probability ◽  
Bias Estimation ◽  
Estimation Of Parameters ◽  
A Posteriori Probability ◽  
Search Volume ◽  
Operation Speed

In order to conduct estimation of parameters in signal processing, using maximum likelihood estimate and the minimum mean square error estimate and maximum a posteriori probability in Bayes estimate . The experimental results show that: the maximum likelihood estimate accuracy, but search volume greatly; and Bias estimation to a certain extent, can improve the operation speed, but lower precision. So in the actual operation, select appropriate estimate methods based on the specific conditions.

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 Security Improvement in Next Generation Wireless System by Interleaver in Transceiver Structures

2017 ◽  
Author(s):  
B. Partibane ◽  
R. Kalidoss ◽  
R. Karthipan
Keyword(s):  
Interference Cancellation ◽  
Iterative Decoding ◽  
Channel Model ◽  
Minimum Mean Square Error ◽  
Antenna System ◽  
Posteriori Probability ◽  
Decoding Algorithm ◽  
Simulation Results ◽  
Dual Polarized ◽  
Dual Polarized Antenna

This paper presents the multiple-input multiple-output Interleave division multiple access (MIMO-IDMA) system with dual polarized division multiplexing (DPDM). Dual polarized antenna system replaces the uni-polarized antenna system availing cost and space features. We have considered dual- Polarized antennas at both the transmitter and the receiver ends to establish DPDM. For the purpose of accommodation, the users are separated with userspecific interleaver in combination with a low rate spreading sequence. In the receiver, we consider the minimum mean square error (MMSE) algorithm based successive interference cancellation (SIC) Multi-user detection (MUD) technique to diminish the effects of multi-stream interference (MSI). Furthermore, we implement Log-maximum a posteriori probability (MAPP) decoding algorithm at the mobile stations (MSs) to alleviate the effects of multi-user interference (MUI).We evaluate the effects of codedMIMO-IDMA system in the context of downlink (DL) communication pertaining to the Stanford University Interim (SUI) and Long-term Evolution (LTE) channel model specifications.We observe that our simulation results considered turbo coded Dual-PolarizedMIMO-IDMAsystem with iterative decoding algorithm provides a better bit error rate (BER) performance with less signal to noise ratio (SNR) when compared to uncoded system. Furthermore our simulation results show that MIMO-IDMA system with Dual-Polarized antenna requires higher SNR than uni-polarized antennas in order to achieve same BER. However, it provides the advantage of replacing two uni-polarized antennas by a single Dual-Polarized antenna which can therefore help achievement of a higher data rate with a reduced size of MS in the context of DL transmission.  

Sign in / Sign up

Export Citation Format

Share Document