The great development of general-purpose processor technology makes the GPP possess the efficiently massive data processing abilities. In the solution(s) of 3GPP LTE system based on GPP platform, ...Turbo decoding algorithms play a vital role for high decoding complexity. This paper presents the design and implementation of SIMD technique based parallel turbo decoder suitable for GPP architecture. We improve the throughput through a) adopting fix-point design, b) taking full advantage of SIMD technique, c) using multiple soft-input soft-output decoders that operate in parallel, d) introducing multi-core technique to parallelize workload across cores. With 4 threads, the throughput of our SIMD and multi-threading technology based turbo decoder for GPP platform achieves 150 Mbps which can meet the requirement of LTE system.
This paper presents a LTE eNodeB signal processing prototype on commodity PC architectures. LTE is one of the major B3G wireless communication systems with large throughput. Meanwhile, general ...purpose processor (GPP) techniques such as single instruction multi data technique, cache technique and many other effective techniques are developing rapidly in recent years. Thus, we apply Nehalem, one of the primary commodity PC architectures of Intel, to achieve the LTE eNodeB signal processing functions. We complete our single-core version test and reveal that the GPP platform has great potential for the development of real-time wireless signal systems.
Currently the ASIC applications such as multimedia processing require shorter time-to-market and higher performance. Furthermore, with the IC manufacturing technology developing continually, from ...transistor level to logic gate level, the size of standard cells in digital circuits is increasing correspondingly. New methodology should be proposed to meet the need for shorter time-to-market IC industry, and the requirement of advanced IC manufacturing technology. This paper proposed the concept and principle of operator design methodology, then focused on the entropy coding application by the reconfigurable operator and finally gave the synthesis data. The results show that compared with the hardware design at the same cost of resources, this methodology can obtain hardware of suitable performance with regular structure. What is more, it can improve the design speed efficiently.
In this paper, the problem of exploiting potential benefit from centralized processing nature of cloud base-station is addressed. We propose to exploit one kind of benefit available in cloud ...base-station, called scale effects, for MIMO detection by employing the scale effects oriented MIMO detector (SEOD). From this study, it can be found that SEOD is a feasible scheme being able to exploit two types of scale effects. The first type, called scale effect on diversity order, denotes the feature that the worst-case complexity per user of MIMO detection could decrease as the number of users increases while bringing no loss of diversity order; the second one, called scale effect on detecting outage, is the feature that the probability of detecting outage owing to the run-time limit is equal to or is asymptotic to a monotonic decreasing function of the number of users when fixing the worst-case complexity per user for MIMO detection. By using the large deviation principle (LDP), this work presents the proof of the existence of scale effect on detecting outage in SEOD which has not been obtained in literatures. Provided SEOD as a representative case, we also state the universal significance of exploiting scale effects for cloud base-station.
Low Complexity LMMSE Channel Estimation on GPP Wei Shi; Tao Peng; Rongrong Qian ...
7th International Conference on Communications and Networking in China,
2012-Aug.
Conference Proceeding
This paper proposes an improved linear minimum mean square error (LMMSE) algorithm of adaptive order determination by taking advantage of the structure characteristics of time domain least square ...(LS) channel estimation based on general-purpose processor (GPP), which provides the approximate estimation approach of max-time delay and noise power. In addition, this algorithm achieves a practical channel estimation formula which greatly reduces the complexity of the algorithm by decomposing the autocorrelation matrix into some sub-matrixes on the foundation of correlation bandwidth. Then comparisons are made between the simulation performance of improved LMMSE algorithm with those of other estimation methods for further analysis. Finally, a hardware implementation scheme of the proposed algorithm on GPP is given.
Currently ASIC applications, such as multimedia processing, require shorter time-to-market and lower cost of Non Recurring Engineering (NRE). Also, with the IC manufacturing technology developing ...continually, from transistor level to logic gate level, the size of design cells in digital circuits is increasing correspondingly. New design methodology is in urgent need to meet the requirement for the developing processing technology and shorter time-to-market in IC industry. This paper proposed the concepts and principles of operator design methodology, then focused on the entropy coding application based on the operators and finally presented the implementation results. The results show that with the proposed methodology, a comparable hardware performance can be obtained against the traditional standard cell based design flow. Furthermore, the design speed can be improved efficiently.
To deal with the multi-path delay spread in non- line-of-sight (NLOS) environments, single-carrier frequency- domain equalization (SC-FDE), a.k.a., single-carrier block transmission (SCBT), is ...thought to be an effective alternative of orthogonal frequency division multiplexing (OFDM). On the other hand, the low-density parity-check (LDPC) coding is considered as the high-performance channel coding scheme due to its good tradeoff between performance and complexity. To facilitate using LDPC for SC-FDE, we proposed a virtual channel based log-likelihood ratio (LLR) calculation method aided by the Unique Word (UW). The proposed method can significantly improve the LDPC decoding performance in SC-FDE system, and does not need additional overhead or complexity. This is very promising to support ultra high-data-rate wireless transmission.
This thesis considers the problem in data-driven modeling for quality control of complex chemical processes characterized by nonlinearity and time-varying dynamics over a wide range of operating ...conditions. The critical steps in data-driven modeling for quality control, such as data pretreatment, online inferential model maintenance and quality control mechanism designs, are investigated separately in previous studies, which calls for holistic research on those topics.;
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In the initial phase of this research, the missing measurement problem in data-driven modeling is addressed by two developed probabilistic partial least squares (PPLS) methods. In the expectation-maximization (EM) based PPLS (EM-PPLS), the convergence properties for model parameters and estimated values of missing measurements are proved in explicit forms, enabling effective and robust application. In parallel, full Bayesian treatment is employed in the Bayesian inference based PPLS (BI-PPLS), to substantially reduce the computational complexity in latent variable selection in the PPLS model. In both proposed PPLS methods, data-driven model generation and missing measurement estimation can be carried out concurrently along with the uncertainty handling in process measurements through a probabilistic strategy.;
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Next, the degradation problem in the online implementation of the data-driven inferential models is addressed. The discrepancy between the actual model parameters in the data-driven model and filtered model parameters by Kalman filter is calculated and utilized to derive a model mismatch index, decomposition of which can further lead to identification of leading abnormal model parameters in the data-driven model. With the developed model mismatch index, an online model update strategy is developed to maintain the data-driven inferential model online.;
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Finally, a predictive controller based on multiple data-driven dynamic and inferential models is designed to control the final product quality in the batch processes. The entire batch is divided into several modeling phases based on the availability of intermittent quality measurements, in which local dynamic models are identified using weighted autoregressive exogenous (ARX) models. Meanwhile, multiway PLS (MPLS) models are also constructed to predict the quality at batch termination given the intermittent quality measurements at the initiation of each modeling phase. The data-driven models are integrated within model predictive control (MPC) framework to control the final product quality in Penicillin fermentation process with the consideration of causality relationships between the future inputs and final product quality.
Thesis
Master of Applied Science (MASc)
In this paper we propose several novel HARQ schemes for MIMO system which jointly utilize bit-wise soft- information (BWSI) chase combining. Retransmission mechanisms to obtain ARQ diversity are ...developed. We present the detection algorithm and how to jointly utilize the BWSI derived from former retransmission to improve BER performance. Finally we propose a new retrans scheme using channel codes based on BWSI feedback, which can achieve better performance compared to normal HARQ with acceptable complexity.
MIMO Transceiver Scheme Based on Singular Linear Transform Lee, Li; Chen, Kuilin; Fang, Lintang ...
2008 4th IEEE International Conference on Circuits and Systems for Communications,
2008, Volume:
4
Conference Proceeding, Journal Article
Multiple input multiple output (MIMO) wireless systems have gained increasing attention today. Based on research for the known spatial multiplexing detection algorithms, in order to improve BER ...performance and decrease the computational complexity, we propose a MIMO transceiver scheme using singular linear transformation (SLT) in this paper. In this scheme, the transmitted signal vectors with a proper time interval are combined together by an optimizing singular linear matrix. The signal detection at the receiver includes the coarse estimator based on zero forcing (ZF) filter and the fine estimator based on parallel interference cancelation (PIC). Simulation results show that this novel MIMO scheme can improve the receive diversity order, improve the Bit Error Rate (BER) performance, and decrease the computational complexity without loss in spectrum efficiency.
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