Log-likelihood-ratio ordered successive interference cancellation in multi-user, multi-mode MIMO systems

2008 ◽  
Vol 12 (11) ◽  
pp. 837-839 ◽  
Author(s):  
Young Chun ◽  
Sang Kim
Keyword(s):  
Likelihood Ratio ◽  
Interference Cancellation ◽  
Mimo Systems ◽  
Successive Interference Cancellation ◽  
Log Likelihood ◽  
Log Likelihood Ratio ◽  
Multi Mode

A Novel Transmit Diversity Technique for MIMO System

2012 ◽  
Vol 468-471 ◽  
pp. 355-359
Author(s):  
You Yan Zhang ◽  
Shu Yue Hong
Keyword(s):  
Likelihood Ratio ◽  
Mimo Systems ◽  
Antenna Selection ◽  
Mimo System ◽  
Signal To Noise Ratio ◽  
Gray Code ◽  
Transmit Antenna Selection ◽  
Selection Scheme ◽  
Log Likelihood ◽  
Log Likelihood Ratio

The antenna diversity based on log-likelihood ratio (LLR) is better than that based on signal-to-noise ratio (SNR) in bit error rate performance for MIMO systems. Thus in this paper, we present a novel transmit antenna selection scheme based on bit log-likelihood ratio when the Alamouti code is employed .Then the BER expressions of application based on Bit-LLR (BLLR) for MPSK and MQAM modulation with Gray code are derived. The simulation results show that the new scheme based on BLLR is superior to SNR. With the increase of the transmit antennas, the performance of system is improved significantly. Furthermore, the diversity order is the same as that of the full complexity systems.

scholarly journals Performance of non-orthogonal multiple access downlink system using the Log-Likelihood ratio

2020 ◽  
Vol 4 (3) ◽  
pp. First
Author(s):  
Khoa Le Dang ◽  
Thanh Hai Ngo ◽  
Nghia Thai Cong Nguyen
Keyword(s):  
Likelihood Ratio ◽  
Interference Cancellation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Access ◽  
Additive White Gaussian Noise ◽  
Multiple Input Multiple Output ◽  
Time Frequency ◽  
Log Likelihood ◽  
Log Likelihood Ratio ◽  
Downlink System

Non-orthogonal multiple access (NOMA) is one of the potential technologies for fifth generation (5G) cellular networks. This technique can combine with other techniques such as Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO). In NOMA downlink, signals from multiple users are superposed in time-frequency domain. Hence, NOMA systems have a larger throughput than orthogonal multiple access systems. There are several schemes for NOMA detection. The successive interference cancellation (SIC) is commonly used to decode desired signals at the receivers. Some NOMA schemes with SIC are ideal SIC, symbol-level SIC and codeword-level SIC. The previous studies showed that the log-likelihood ratio (LLR) has a performance as ideal SIC. In this paper, we derive the bit error rate for a NOMA downlink system with 2 users (UE) using LLR receiver. This study considers the system over a Rayleigh fading channel and the presence of Additive White Gaussian Noise. The closed-form equations have been proposed for each user with QPSK mapping. The simulation results show that the performance of the system is consistent with the proposed formula

scholarly journals A Corpus-Based Study on the Use of the Logical Connector ‘Thus’ in the Academic Writing of Turkish EFL Learners

2017 ◽  
Vol 10 (2) ◽  
pp. 64
Author(s):  
Serpil Ucar ◽  
Ceyhun Yukselir
Keyword(s):  
Likelihood Ratio ◽  
Academic Writing ◽  
Native Speakers ◽  
American English ◽  
Advanced Learners ◽  
Efl Learners ◽  
Log Likelihood ◽  
Log Likelihood Ratio ◽  
Effect Relation ◽  
Academic Genre

This research was conducted to investigate how frequently Turkish advanced learners of English use the logical connector ‘thus’ in their academic prose and to investigate whether it was overused, underused or misused semantically in comparison to English native speakers. The data were collected from three corpora; Corpus of Contemporary American English and 20 scientific articles of native speakers as control corpora, and 20 scientific articles of Turkish advanced EFL learners. The raw frequencies, frequencies per million words, frequencies per text and log-likelihood ratio were measured so as to compare varieties across the three corpora. The findings revealed that Turkish learners of English showed underuse in the use of the connector ‘thus’ in their academic prose compared to native speakers. Additionally, they did not demonstrate misuse in the use of the connector ‘thus’. Nevertheless, non-native learners of English tended to use this connector in a resultative role (cause-effect relation) more frequently whereas native speakers used it in appositional and summative roles more as well as its resultative role. Furthermore, the most frequent occurrences of ‘thus’ have been in academic genre.

Sign in / Sign up

Export Citation Format

Share Document