247 research outputs found
Turbo receivers for interleave-division multiple-access systems
In this paper several turbo receivers for Interleave-Division Multiple-Access (IDMA) systems will be discussed. The multiple access system model is presented first. The optimal, Maximum A Posteriori (MAP) algorithm, is then presented. It will be shown that the use of a precoding technique at the emitter side is applicable to IDMA systems. Several low complexity Multi-User Detector (MUD), based on the Gaussian approximation, will be next discussed. It will be shown that the MUD with Probabilistic Data Association (PDA) algorithm provides faster convergence of the turbo receiver. The discussed turbo receivers will be evaluated by means of Bit Error Rate (BER) simulations and EXtrinsic Information Transfer (EXIT) charts
A Universal Receiver for Uplink NOMA Systems
Given its capability in efficient radio resource sharing, non-orthogonal
multiple access (NOMA) has been identified as a promising technology in 5G to
improve the system capacity, user connectivity, and scheduling latency. A dozen
of uplink NOMA schemes have been proposed recently and this paper considers the
design of a universal receiver suitable for all potential designs of NOMA
schemes. Firstly, a general turbo-like iterative receiver structure is
introduced, under which, a universal expectation propagation algorithm (EPA)
detector with hybrid parallel interference cancellation (PIC) is proposed (EPA
in short). Link-level simulations show that the proposed EPA receiver can
achieve superior block error rate (BLER) performance with implementation
friendly complexity and fast convergence, and is always better than the
traditional codeword level MMSE-PIC receiver for various kinds of NOMA schemes.Comment: This paper has been accepted by IEEE/CIC International Conference on
Communications in China (ICCC 2018). 5 pages, 4 figure
EXIT-charts-aided hybrid multiuser detector for multicarrier interleave-division multiple access
A generically applicable hybrid multiuser detector (MUD) concept is proposed by appropriately activating different MUDs in consecutive turbo iterations based on the mutual information (MI) gain. It is demonstrated that the proposed hybrid MUD is capable of approaching the optimal Bayesian MUD's performance despite its reduced complexity, which is at a modestly increased complexity in comparison with that of the suboptimum soft interference cancellation (SoIC) MU
(SI10-062) Comprehensive Study on Methodology of Orthogonal Interleavers
Interleaving permutes the data bits by employing a user defined sequence to reduce burst error which at times exceeds the minimum hamming distance. It serves as the sole medium to distinguish user data in the overlapping channel and is the heart of Interleave Division Multiple Access (IDMA) scheme. Versatility of interleavers relies on various design parameters such as orthogonality, correlation, latency and performance parameters like bit error rate (BER), memory occupancy and computation complexity. In this paper, a comprehensive study of interleaving phenomenon and discussion on numerous interleavers is presented. Also, the BER performance of interleavers using IDMA scheme is displayed
Performance Evaluation of Maximal Ratio Receiver Combining Diversity with Prime Interleaver for Iterative IDMA Receiver
The antenna diversity mechanism is established as the well known mechanism for reduction of probability of occurrence of communication failures (outages) caused by fades. In receiver diversity, multiple antennas are employed at the receiver side in case of transmitter diversity, multiple antennas are the integral part of transmitter section.. In this paper, Maximal Ratio Receiver Combining (MRRC) diversity technique is evaluated to mitigate the effect of fading in IDMA scheme employing random interleaver and prime interleaver with single transmit two receiving antennas in low rate coded environment. For the performance evaluation, channel is assumed to be Rayleigh multipath channel with BPSK modulation. Simulation results demonstrate the significant improvement in BER performance of IDMA with maximal ratio receiver combining (MRRC) diversity along with prime interleaver and random interleaver and it has also been observed that BER performance of prime interleaver is similar to that of random interleaver with reduced bandwidth and memory requirement at transmitter and receiver side. Keywords: Multipath Fading, MRRC diversity, Multi user detection, Interleave-Division Multiple Access (IDMA) Scheme, Random Interleaver, Prime Interleave
Capacity-Achieving Iterative LMMSE Detection for MIMO-NOMA Systems
This paper considers a iterative Linear Minimum Mean Square Error (LMMSE)
detection for the uplink Multiuser Multiple-Input and Multiple-Output (MU-MIMO)
systems with Non-Orthogonal Multiple Access (NOMA). The iterative LMMSE
detection greatly reduces the system computational complexity by departing the
overall processing into many low-complexity distributed calculations. However,
it is generally considered to be sub-optimal and achieves relatively poor
performance. In this paper, we firstly present the matching conditions and area
theorems for the iterative detection of the MIMO-NOMA systems. Based on the
proposed matching conditions and area theorems, the achievable rate region of
the iterative LMMSE detection is analysed. We prove that by properly design the
iterative LMMSE detection, it can achieve (i) the optimal sum capacity of
MU-MIMO systems, (ii) all the maximal extreme points in the capacity region of
MU-MIMO system, and (iii) the whole capacity region of two-user MIMO systems.Comment: 6pages, 5 figures, accepted by IEEE ICC 2016, 23-27 May 2016, Kuala
Lumpur, Malaysi
Decision Feedback Aided Bayesian Turbo Space-Time Equalizer for Parallel Interference Cancellation in SDMA Systems
A novel Bayesian Decision-Feedback aided turbo Space-Time Equalizer (DF-STE) combined with a Parallel Interference Cancellation (PIC) scheme and designed for multiple antenna assisted receivers is introduced. The proposed receiver structure allows the employment of a non-linear Bayesian turbo DF-STE operating at a moderate computational cost, which outperforms the linear turbo detector benchmarker based on the Minimum Mean-Squared Error (MMSE) criterion, even if the latter aims for jointly detecting all transmittersâ signals
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