Дисертації з теми "MIMO decoder"
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Krishnan, Praveen G. "Fast sphere decoder for MIMO systems." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.umr.edu/thesis/pdf/umrthes_09007dcc80318823.pdf.
Повний текст джерелаVita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 16, 2007) Includes bibliographical references (p. 38).
Quesenberry, Joshua Daniel. "Communication Synthesis for MIMO Decoder Matrices." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/51149.
Повний текст джерелаThis framework, which is controlled by a microsequencer, is centered on a matrix-based memory structure comprised of 64 individual dual-ported memory blocks. The microsequencer uses an instruction word that can control every element of the architecture during a single clock cycle. Routing to and from the memory structure uses an optimized form of a crossbar switch with predefined routing paths supporting any combination of input/output pairs needed by the algorithm.
A goal at the start of the design was to achieve a clock speed of over 100 MHz; a clock speed of 183 MHz has been achieved. This design is capable of performing a 4x4 matrix inversion within 335 clock cycles, or 1,829 ns. The power efficiency of the design is measured at 17.15 MFLOPS/W.
Master of Science
Mohammed, Karim Ossama. "A MIMO decoder accelerator for next generation wireless communications." Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=1875366181&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Повний текст джерелаPatel, Vipul Hiralal. "A system on programmable chip approach for MIMO lattice decoder." ScholarWorks@UNO, 2004. http://louisdl.louislibraries.org/u?/NOD,167.
Повний текст джерелаTitle from electronic submission form. "A thesis ... in partial fulfillment of the requirements for the degree of Master of Science in the Department of Electrical Engineering."--Thesis t.p. Vita. Includes bibliographical references.
Lim, Melvin Chi Hearn. "Linear Precoder and Decoder Design for the Multiuser MIMO Downlink." Thesis, University of Leeds, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509007.
Повний текст джерелаKapfunde, Goodwell. "Near-capacity sphere decoder based detection schemes for MIMO wireless communication systems." Thesis, University of Hertfordshire, 2013. http://hdl.handle.net/2299/11350.
Повний текст джерелаSingh, Arun Kumar. "Le compromis Débit-Fiabilité-Complexité dans les systèmes MMO multi-utilisateurs et coopératifs avec décodeurs ML et Lattice." Thesis, Paris, ENST, 2012. http://www.theses.fr/2012ENST0005/document.
Повний текст джерелаIn telecommunications, rate-reliability and encoding-decoding computational complexity (floating point operations - flops), are widely considered to be limiting and interrelated bottlenecks. For this reason, any attempt to significantly reduce complexity may be at the expense of a substantial degradation in error-performance. Establishing this intertwined relationship constitutes an important research topic of substantial practical interest. This dissertation deals with the question of establishing fundamental rate, reliability and complexity limits in general outage-limited multiple-input multiple-output (MIMO) communications, and its related point-to-point, multiuser, cooperative, two-directional, and feedback-aided scenarios. We explore a large subset of the family of linear lattice encoding methods, and we consider the two main families of decoders; maximum likelihood (ML) based and lattice-based decoding. Algorithmic analysis focuses on the efficient bounded-search implementations of these decoders, including a large family of sphere decoders. Specifically, the presented work provides high signal-to-noise (SNR) analysis of the minimum computational reserves (flops or chip size) that allow for a) a certain performance with respect to the diversity-multiplexing gain tradeoff (DMT) and for b) a vanishing gap to the uninterrupted (optimal) ML decoder or a vanishing gap to the exact implementation of (regularized) lattice decoding. The derived complexity exponent describes the asymptotic rate of exponential increase of complexity, exponential in the number of codeword bits
Sevelimedu, Veeravalli Vinodh. "Study of MIMO, orthogonal codes and core operator architecture design for ML decoder." Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10155.
Повний текст джерелаIn the high-end research process of wireless systems and in the race for the development of the new technologies, MIMO (Multiple Input, Multiple Output) is getting more attention now days. It has a high potential usage in the 3G and 4G communications and beyond. The MIMO based system has got the ability to increase the data throughput in spectrum-limited conditions. With the increase and complexity of wireless applications, the spectrum efficiency improvement in the physical layer will be saturated. MIMO is predicted to be one of the major features for the next generation wireless networking. This thesis work is a part of an ongoing project of the Generic MIMO decoder design carried out at the research laboratory, LESTER at Lorient, France. I was involved in the study of MIMO concepts, orthogonal and Space-time codes and later involved in the design and optimization of the architecture for the core operator for the ML decoder used in the reception of the MIMO system,which is presented in this report work.
Correia, Tiago Miguel Pina. "FPGA implementation of Alamouti encoder/decoder for LTE." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12679.
Повний текст джерелаMotivados por transmissões mais rápidas e mais fiáveis num canal sem fios, os sistemas da 4G devem proporcionar processamento de dados mais rápido a baixa complexidade, elevadas taxas de dados, assim como robustez na performance reduzindo também, a latência e os custos de operação. LTE apresenta, na sua camada física, tecnologias como OFDM e MIMO que prometem alcançar elevadas taxas de dados e aumentar a eficiência espectral. Especificamente a camada física do LTE emprega OFDMA para downlink e SC-FDMA para uplink. A tecnologia MIMO permite também melhorar significativamente o desempenho dos sistemas OFDM com as vantagens de multiplexação e diversidade espacial diminuindo o efeito de desvanecimento de multi-percurso no canal. Nesta dissertação são implementados um codificador e um descodificador com base no algoritimo de Alamouti num sistema MISO nomeadamente para serem incluídos num OFDM transceiver que segue as especificações da camada física do LTE. A codificação/descodificação de Alamouti realiza-se no espaço e frequência e os blocos foram projetados e simulados em Matlab através do ambiente Simulink com o auxílio dos blocos da Xilinx inseridos no seu software System Generator para DSP. Pode-se concluir que os blocos baseados no algoritmo de Alamouti foram implementados em hardware com sucesso.
Motivated by faster transmissions and more reliable wireless channel, future 4G systems should provide faster data processing at low complexity, high data rates, as well as robustness in performance while also reducing the latency and operating costs. LTE presents in its physical layer technologies such as OFDM and MIMO that promise to achieve high data rates and increase spectral efficiency. Specifically the physical layer of LTE employs OFDMA on the downlink and SC-FDMA for uplink. MIMO technology also allows to significantly improve the performance of OFDM systems with the advantages of multiplexing and spatial diversity by decreasing the effect of multipath fading in the channel. In this thesis we implemented an encoder and a decoder based on an Alamouti algorithm in a MISO system namely to be added to an OFDM transceiver that follows closely the LTE physical layer specifications. Alamouti coding/decoding is performed in frequency and space and the blocks were projected and simulated in Matlab using Simulink environment through the Xilink's blocks in the System Generator for DSP. One can conclude that the blocks based on Alamouti algorithm were well-implemented.
El, chall Rida. "Récepteur itératif pour les systèmes MIMO-OFDM basé sur le décodage sphérique : convergence, performance et complexité." Thesis, Rennes, INSA, 2015. http://www.theses.fr/2015ISAR0019/document.
Повний текст джерелаRecently, iterative processing has been widely considered to achieve near-capacity performance and reliable high data rate transmission, for future wireless communication systems. However, such an iterative processing poses significant challenges for efficient receiver design. In this thesis, iterative receiver combining multiple-input multiple-output (MIMO) detection with channel decoding is investigated for high data rate transmission. The convergence, the performance and the computational complexity of the iterative receiver for MIMO-OFDM system are considered. First, we review the most relevant hard-output and soft-output MIMO detection algorithms based on sphere decoding, K-Best decoding, and interference cancellation. Consequently, a low-complexity K-best (LCK- Best) based decoder is proposed in order to substantially reduce the computational complexity without significant performance degradation. We then analyze the convergence behaviors of combining these detection algorithms with various forward error correction codes, namely LTE turbo decoder and LDPC decoder with the help of Extrinsic Information Transfer (EXIT) charts. Based on this analysis, a new scheduling order of the required inner and outer iterations is suggested. The performance of the proposed receiver is evaluated in various LTE channel environments, and compared with other MIMO detection schemes. Secondly, the computational complexity of the iterative receiver with different channel coding techniques is evaluated and compared for different modulation orders and coding rates. Simulation results show that our proposed approaches achieve near optimal performance but more importantly it can substantially reduce the computational complexity of the system. From a practical point of view, fixed-point representation is usually used in order to reduce the hardware costs in terms of area, power consumption and execution time. Therefore, we present efficient fixed point arithmetic of the proposed iterative receiver based on LC-KBest decoder. Additionally, the impact of the channel estimation on the system performance is studied. The proposed iterative receiver is tested in a real-time environment using the MIMO WARP platform
Jaldén, Joakim. "Detection for multiple input multiple output channels : analysis of sphere decoding and semidefinite relaxation." Doctoral thesis, KTH, Signalbehandling, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4199.
Повний текст джерелаEtt grundläggande problem som påträffats inom digital kommunikation är detektering av en symbolvektor, tillhörande ett ändligt symbolalfabet, som sänts över en MIMO (från engelskans multiple-input multiple-output) kanal med Gausiskt brus. Detta problem påträffas bland annat då symboler sänts över en trådlös kanal med flera antenner hos mottagaren och sändaren samt då flera användare i ett CDMA system simultant skall avkodas. In denna avhandling behandlas två mottagaralgoritmer konstruerade för detta ändamål. Algoritmerna har sin bakgrund i andra forskningsområden men kan i nuläget sägas vara mycket välkända inom kommunikationsområdet. De benämns vanligtvis som sfäravkodaren (eng. sphere decoder) samt den semidefinita relaxeringsdetektorn (eng. semidefinite relaxation detector). Algoritmerna analyseras i denna avhandling matematiskt genom att införa förenklande antaganden som är relevanta och applicerbara för de kommunikationsproblem som är av intesse. Den första algoritmen, sfäravkodaren, löser dessa detektionsproblem på ett optimalt sätt i betydelsen att den minimerar sannolikheten för att detektorn fattar ett felaktigt beslut rörande det sända meddelandet (symbolvektorn). Också vad gäller algoritmens komplexitet har simuleringar visat att den är oväntat låg, åtminstone vid höga signalbrusförhållanden (SNR). Trots att det är allmänt känt att algoritmen i sämsta fall har exponentiell komplexitet så har detta lett till den allmänt spridda uppfattningen att medelkomplexiteten (eller den förväntade komplexiteten) endast är polynomisk vid höga signalbrusförhållanden. Ett av huvudbidragen i denna avhandling är att visa att denna uppfattning är felaktig och att också medelkomplexiteten växer exponentiellt i antalet symboler som simultant detekteras. Ytterligare ett bidrag ligger i att ge en alternativ förklaring till den observerat låga medelkomplexiteten. Det visas att den exponentiella hastighet med vilken komplexiteten växer beror på signalbrusförhållande, och att den är låg för höga SNR. Den andra algoritmen, den semidefinita relaxeringsdetektorn, erbjuder polynomisk komplexitet vid en något högre felsannolikhet. Intressant nog har dock felsannolikheten tidigare, genom simuleringar, visat sig vara endast marginellt högre än felsannolikheten hos den optimala mottagaren. Bidraget som relaterar till den semidefinita relaxeringsmottagaren ligger i att både förklara och i att ge en specifik kvatifierbar mening åt uttalandet att felsannolikheten endast är marginellt högre. I syfte att åstadkomma detta studeras diversitetsordningen för detektorn, och det bevisas att diversitetsordningen för den semidefinita relaxeringsdetektorn är densamma som för den optimala mottagaren. Utöver detta karakteriseras också de krav som måste uppfyllas för att den detektorn skall finna den optimala lösningen.
QC 20100901
Palanivelu, Arul Durai Murugan. "Tree search algorithms for joint detection and decoding." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1145039374.
Повний текст джерелаBarbero, Liñan Luis G. "Rapid prototyping of a fixed-complexity sphere decoder and its application to iterative decoding of turbo-MIMO systems." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/11903.
Повний текст джерелаYounis, Abdelhamid. "Spatial modulation : theory to practice." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/8990.
Повний текст джерелаAubert, Sébastien. "Advanced Techniques for Achieving Near Maximum-Likelihood Soft Detection in MIMO-OFDM Systems and Implementation Aspects for LTE/LTE-A." Phd thesis, INSA de Rennes, 2011. http://tel.archives-ouvertes.fr/tel-00730797.
Повний текст джерелаXIAO, GUOPING. "VLSI architectures design for encoders of High Efficiency Video Coding (HEVC) standard." Doctoral thesis, Politecnico di Torino, 2016. http://hdl.handle.net/11583/2644058.
Повний текст джерелаHICKS, CHRISTOPHER D. "PERFORMANCE ANALYSIS OF MIMO LINEAR PRECODERS/DECODERS." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1154397576.
Повний текст джерелаVaradarajan, Badri. "The Design of Linear Space-Time Codes for Quasi-static Flat-fading Channels." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5030.
Повний текст джерелаLiang, Ying, and 梁瑩. "A study on low complexity near-maximum likelihood spherical MIMO decoders." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B43703987.
Повний текст джерелаLiang, Ying. "A study on low complexity near-maximum likelihood spherical MIMO decoders." Click to view the E-thesis via HKUTO, 2010. http://sunzi.lib.hku.hk/hkuto/record/B43703987.
Повний текст джерелаLiang, Cao. "Hardware/Software Co-Design Architecture and Implementations of MIMO Decoders on FPGA." ScholarWorks@UNO, 2006. http://scholarworks.uno.edu/td/416.
Повний текст джерелаJin, Jie. "Low power design for high performance wireless digital baseband building blocks /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20JIN.
Повний текст джерелаAzarian, Yazdi Kambiz. "Outage limited cooperative channels protocols and analysis /." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1154740723.
Повний текст джерелаLiao, Yen-Chin, and 廖彥欽. "Research on Sphere/LDPC Decoder for Coded-MIMO Systems." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/10789537397358749203.
Повний текст джерела國立交通大學
電子工程系所
96
This dissertation presents algorithm designs for sphere decoders and low-density parity check (LDPC) code decoders in multi-input multi-output (MIMO) systems from implementation point of view. Based on statistical techniques, complexity reduction schemes are proposed. Sphere decoders of hard-decision outputs and LDPC decoding algorithms in AWGN channel are discussed first. Then the sphere decoders with soft-decision outputs for channel-coded MIMO systems are investigated. Sphere decoding algorithm is one realization of maximum likelihood signal detection for MIMO systems, and the computation can vary with channel due to the fading phenomena. Among several modified algorithms, K-best algorithm is suitable for hardware implementation for the constant computation and predictable hardware complexity. However, K-best algorithm has to be realized with the assumption of worst channel condition in order to maintain the system performance. For complexity reduction, an early pruning scheme combined with K-best algorithm is presented. According to the system model and channel statistics the expected complexity can be analyzed as well. Based on the complexity analysis, an early-pruned multi-K-best algorithm is proposed by which the lowest decoding speed can be further improved. The simulation results in 64-QAM 4 × 4 MIMO channel show that 90% complexity can be reduced with imperceptible degradation in both symbol error rate and bit error rate above 10−5. For decoding LDPC codes, min-sum algorithm is one common simplification of Log-BP algorithm, but there is a performance gap due to the approximation inaccuracy. Normalization schemes are investigated to compensate the approximation error. Moreover, the normalization factor can be described by a function of the decoder inputs, noise variance, and the decoding iteration number. The data-dependent correction terms can be analyzed and derived by order statistic and density evolution. Simulated in DVB-S2 system, the dynamic normalization schemes effectively mend the SNR loss from Log-BP algorithm to min-sum algorithm with few normalization overheads, and 1.0dB SNR improvement, which is about 95% of the SNR loss from Log-BP to min-sum algorithm, can be achieved. For channel coded MIMO systems, a sphere decoder is modified to a list sphere decoder that generates a candidate list for computing the soft inputs. Under iterative message passing decoding, the candidate list and the soft value generation impact the decoding convergence. Sufficiently large candidate list is required to avoid error floor. Thus, a path augmentation technique is proposed by which a larger and distinct list can be employed in computing the probabilistic information of each received bit. Compared with directly generating a larger list, path augmentation performs comparatively less operations. In our simulation based on a 64-QAM 4×4 MIMO system with LDPC codes defined in IEEE802.11n, the proposed augmented-list sphere decoder based on 64-best algorithm achieves the lowest error floor and saves about 50% computations, if compared to the standard list sphere decoder which is based on 128-best algorithm. Moreover, by the proposed early pruning scheme and multi-K-best algorithm, 94% reduction in sorting complexity can be achieved.
Hu, Kai-Shiang, and 胡凱翔. "Design of STBC Decoder in MIMO systems for IEEE802.16 standard." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/04596239693248357243.
Повний текст джерела雲林科技大學
電機工程系碩士班
96
This thesis is focused on the investigation of the decoder structure of space-time block code (STBC) in a multiple input multiple output (MIMO) system. At the receiver, the received STBC encoded signals are respectively decoded by using two algorithms, namely, the maximum likelihood (ML) decoder and the least-square zero-forcing (LS-ZF) decoder. The decoding efficiency and hardware complexity for both algorithms are presented. We have found from the simulation results that the performance of an ML decoder is about 4 dB better than that of an LS-ZF decoder. To compare the hardware complexity of the two decoders, we first use Matlab to determine the optimum bit-lengths representing the fractional parts of received data. The results of fixed-point simulation show that the LS-ZF and the ML decoders need 8 bits and 5 bits, respectively. Subsequently, verilog HDL is used to perform the structural design of the circuit over a Modelsim platform. Simulation results demonstrate that the ML decoder outperforms the LS-ZF decoder by about 4 dB. The numbers of logic gates required to build the STBC decoders for the ML and the LS-ZF decoders are 11509 and 9801, respectively. That is, the complexity of an ML decoder is only about 1.17 times of that of an LS-ZF decoder.
Cheng, Yong-Lin, and 鄭詠霖. "Efficient Design of Soft-Ouput Decoder for MIMO-OFDM Systems." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/61839920873329275460.
Повний текст джерела國立中興大學
電機工程學系所
103
As the development of communication technology, demands of high data rates of wireless communications grow rapidly. The multiple antenna system plays an important role. The reason is that channel capacity increases linearly with the minimum number of antennas. Therefore, it has the advantage over the single input single output (SISO) system in terms of high data transmission rates. However, interference between multiple antennas needs to be overcome. In addition, low density parity check (LDPC) codec is added because it can approach the Shannon Limit and helps reduce power consumption in transmission, as well as enhance error correction capability. In this thesis, integration and implementation of multiple input multiple output (MIMO) with LDPC codec systems are performed. They include several parts: theories of MIMO-OFDM and LDPC codec, algorithms of signal detection and circuit design, log-likelihood ratio (LLR) demodulator circuit design, additive white Gaussian noise (AWGN) generator circuit design, integration and design of MIMO-LDPC system. The signal detector was implemented by the K-Best algorithm, which combines the properties of both breadth-first and depth-first algorithms with constant throughput. In comparison with the conventional K-Best, this algorithm using enumeration circuit to obtain the estimated transmitted symbol results in less symbol numbers to expand the best K paths, while the performance is still excellent. For the LLR demodulator, instead of the conventional LLR calculation using partial Euclidean distance (PED), the linear approximated LLR algorithm is used in the LDPC decoder. The integration of MIMO detector with LDPC decoder achieves excellent bit error rate (BER) performance. The Matlab simulation shows the fixed point results very close to the floating point results. When EbN0 = 18 dB for 64-QAM modulation with 44 antennas, the BER can be as low as 10-7. Finally, this MIMO Detector was verified using Xilinx Virtex-7 FPGA board successfully.
Chen, Hsin-Ta, and 陳信達. "A Low Complexity Look-Ahead Sphere Decoder for MIMO Detection." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/12663278057776005265.
Повний текст джерела國立中正大學
通訊工程研究所
99
Traditional depth-first sphere decoder is an algorithm which is capable of obtaining the optimal ML solution by using the idea of tree search. The algorithm has much lower complexity compared to the exhaustive search, but requires reverse searching operations, making the overall complexity varying for different channel realizations. For the ease of hardware implementation, K-best algorithm has been proposed. K-best algorithm finds K nodes of relative small cumulative PED(partial Euclidean distance) in each layer and then traverse down to the next layer. Since no reverse search is required, the K-best algorithm has fixed complexity. In this paper, we introduce a new algorithm based on a new lattice representation and make use of a look-ahead technique to reduce both time and computational complexity of the K-best algorithm. Two further improved algorithm, 4-Layer Early Pruned algorithm and 4-Layer Relaxed K-Best have been proposed to reduce the computational complexity. The complexity of the proposed algorithms has been compared both analytically and via computer simulations. Simulation results showed that the proposed algorithms achieve better error rate and also lower computational complexity compared to the K-best algorithm.
Cheng-Ming, Chen. "A New Reduced-Complexity Sphere Decoder for MIMO Spatial Multiplexing System." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1607200623202900.
Повний текст джерелаChen, Cheng-Ming, and 陳楨明. "A New Reduced-Complexity Sphere Decoder for MIMO Spatial Multiplexing System." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/34656840105342549856.
Повний текст джерела國立臺灣大學
電信工程學研究所
94
In this thesis we propose an algorithm which combines the Sphere Decoding algorithm (SDA) and the Ordered Successive Interference Cancellation algorithm (OSIC) to reduce the computation time of the SDA. We name it SD-OSIC algorithm. This algorithm has the near-ML (Maximum Likelihood) Performance and needs to search fewer lattice points inside the sphere radius, hence the searching problem are reduced to a lower dimension ones. We also derive the number of multiplication and addition operations of SD-OSIC and conventional SDA. Numerical simulation reveals our proposed algorithm requires less loop iterations than conventional SDA and in some scenario SD-OSIC requires less computation power than the SDA. With the supports of these two comparisons, we conclude our algorithm requires less computation time than the conventional SDA.
Cheng-ChiehHuang and 黃政傑. "Low-Complexity MIMO Detector Based on the Fixed-Complexity Sphere Decoder." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/56496529955246061661.
Повний текст джерелаWang, Chihjung, and 王致融. "Low Complexity Soft-Output Detector for MIMO System with Viterbi Decoder." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/25188115470753682658.
Повний текст джерела國立中正大學
通訊工程研究所
99
The multiple-input multiple-output system is able to provide high transmission data rate for wireless communication systems. The baseband MIMO detectors are divided into two categories, the hard-output and soft-output detectors, where the latter one is able to work together with an error control code (ECC) decoder to yield a lower coded BER performance. In the soft-output detector, the soft a posteriori probability (APP) is computed and is to be sent to the following ECC decoder. To provide complete APP information, all possible data must be calculated. This may cause formidable computational complexity. Two well-known low-complexity detectors to provide approximate APP information are the LISt-Sequential detector (LISS) and Layered Orthogonal Lattice Detector (LORD). We consider in this thesis that the following ECC decoder is a soft Viterbi decoder. The input signal to the Viterbi decoder is quantized with different number of bits. The results from computer simulations lead us to conclude that the LORD detector and the LISS detector with few candidates lead to very close coded BER, when QPSK and 16-QAM are used as the modulation and when the two detectors work with the same Viterbi decoder. However, the LORD detector is of fixed complexity and therefore is easier to realize in hardware.
Wang, Hsiao-Chi, and 王曉淇. "A High Throughput Low Complexity Soft-output Sphere Decoder for MIMO Communications." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/82736348986678769250.
Повний текст джерела國立清華大學
電機工程學系
97
In this thesis, a high throughput fixed complexity soft-output sphere decoder supporting QPSK, 16-QAM, and 64-QAM modulation in the 4x4 MIMO system is proposed. For achieving soft-output, the proposed tree search algorithm is presented. Some simulation results help to modify the tree search algorithm of the original fixed-complexity sphere decoder (FSD) for soft-output detection. Compared with the optimal soft-output sphere decoder, the proposed soft-output FSD (SFSD) has a little frame error rate (FER) degradation (0.5dB), but the benefit is that SFSD has fixed complexity and can suit to a parallel or full pipeline hardware design. Moreover, a high throughput hardware architecture is proposed to implement the SFSD algorithm. A simplified enumeration method is proposed to reduce the hardware complexity. The parallel architecture is proposed to achieve high throughput. For the high clock frequency, many pipelines are inserted into the proposed architecture. In addition, the proposed SFSD is implemented by the 0.18um CMOS cell-library of HP laboratory. The area of proposed hardware implementation is about 100k equivalent gates corresponding to the two-input drive-one NAND gate. The maximum throughput can reach to 120Mbps with 16-QAM modulation. Finally, the FPGA emulation is made to verify the proposed design is able to work. Then a high performance high throughput soft-output MIMO detector has completely accomplished in the thesis.
Wang, To-Ping, and 王拓評. "Design of a New Complex Sphere Decoder for Soft-Output MIMO Detection." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/81987854974940585916.
Повний текст джерела國立臺灣大學
電子工程學研究所
95
The services, such as on-line videos, high definition TV (HDTV), interactive games, provided by the next generation wireless communication systems produce the demand for much higher throughput and better Quality of Service (QoS) under the situation of limited bandwidth. Nowadays, OFDM is widely adopted to improve bandwidth utilization in many communication systems and has become the main modulation technique of many standards. In the future, MIMO will be the next widely accepted technique because of its provision for diversity and spectrum efficiency. MIMO system can easily satisfy the demand for high throughput by increasing the number of transmit and receive antennas. For the QoS concern, the detection complexity grows exponential with the antenna number in theory. Corresponding literatures propose sphere decoder to mitigate this problem and conserve the near ML performance. However, the arithmetic complexity is still much more than other detection schemes. In order to overcome this trade-off problem, the thesis combines modified tabular enumeration and best-first tree search algorithm and therefore proposes the new sphere decoding algorithm: modified best-first (MBF) algorithm. After mathematic induction and software simulation by the iterative MIMO detection & decoding system, we demonstrate that MBF can not only reduce the enumeration complexity, especially for high-order QAM, but also conserve high performance from the characteristic of the best-first algorithm. Besides, in order to avoid the performance attenuation of high dimension MIMO system, we integrate successive interference cancellation algorithm, early termination algorithm and MBF into proposed MBF-SIC algorithm. Finally, we give the hardware design to show that the proposed soft-output MIMO complex-plane sphere decoder composed of MBF-SIC is reasonable for hardware implementation.
Lee, Tsung-Hsueh, and 李宗學. "Design and Implementation of a New Complex Sphere Decoder for MIMO Detection." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/84274405802171326659.
Повний текст джерела國立臺灣大學
電子工程學研究所
95
More and more services are provided in the next generation wireless communicaiton systems, including on-line videos, high definition TV (HDTV), interactive games and so on. The demand for throughput and QoS is getting higher. However, the bandwidth is limited. OFDM is widely adopted in many communication systems and has become a main modulation technique of many standards. MIMO will be the next widely accepted technique because of its provision for diversity and/or spectrum efficiency. To apply the MIMO techniques, the number of transmitting and receiving antennas needs be more than one. Among spatial multiplexing MIMO detection, sphere decoding algorithm is the first that was proposed to do maximum-likelihood equalization’detection with acceptable complexity. In the thesis, sphere decoder related literatures are surveyed and a new complex-plane sphere decoder is designed and implemented. Depth-first search with closest point first order is introduced directly on complex-valued signals. List-Enumeration algorithm is proposed to overcome the problem of enumeration in complex-plane sphere decoder. The list can be implemented by either an unified list and several individual lists. In addition, backward-Layer controlled algorithm and diminished dimensionality algorithm are proposed to further reduce the hardware complexity. Two architectures, parallel forward/backward search and single calculation unit, are proposed to implement the new algorithm. The tradeoffs of these two versions are between area, power, and throughput. The hardware can support different constellations and numbers of antennas. Simulation and implementation results indicate the proposed algorithm and architecture outperform other solutions and form a solid foundation for future wireless communication systems that adopt MIMO processing.
Lin, Hsin-Lei, and 林心蕾. "Design of Synchronization and Decoder Circuits for MIMO-OFDM Wireless Communication Systems." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/33916429550633495617.
Повний текст джерела國立中興大學
電機工程學系所
96
The designs of synchronization and MIMO decoder are proposed in this dissertation since the MIMO method and OFDM technique can be used for improving either the performance or the data rate of wireless communication. The synchronization is investigated since the frequency is more sensitive in OFDM system. A novel digital oscillator of synchronization combined with the CORDIC algorithm and Sinusoidal function is designed for the MIMO wireless communication. The synchronization was implemented using TSMC 0.18 μm 1P6M CMOS technology at 1.8V, and the core area was about 1.682 mm^2 of a 2-by-2 antenna system. A memory-based oscillator needs an accumulator and a sin/cos generator to perform frequency compensation, and the size of memory severely limits the precision. The proposed circuit reduces the memory by using sinusoidal. Furthermore, comparing to the iterative CORDIC computation, the proposed CSIO architecture operates the CORDIC only once. Moreover, a high throughput and low-cost JVBPSD algorithm using efficient candidate searching is proposed for SDM-MIMO wireless system. It can operate at a 166 MHz clock frequency, and the average throughput of the efficient candidate searching MIMO decoder is 95 Mbps with 64-QAM modulation at 30 dB SNR. The core area of the proposed MIMO decoder using a TSMC 90nm technology with different modulations in a 4-by-4 SDM-MIMO wireless system is about 0.675 mm^2.
Chen, Chieh-Yu, and 陳婕妤. "Power-Aware Space-Time-Trellis-Coded MIMO Decoder with Embedded SNR Estimator." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/46414151585951822334.
Повний текст джерела國立清華大學
電機工程學系
99
Space-time trellis code (STTC) has been widely applied to coded multiple-input multiple-output (MIMO) systems because of its gains in coding and diversity. However, its great decoding complexity makes it less promising in chip realization compared to the space-time block code (STBC). The complexity of STTC decoding lies in the branch metric calculation in the Viterbi algorithm. Compared with the Viterbi decoder for convolutional code, the STTC Viterbi decoder has a large amount of the complex-number multiplications to calculate the branch metrics. Besides, the amount of the branch metric calculations increases significantly in proportional with the number of antennas and the modulation order. The large amount of calculation and complexity design is a major result that STTC code is not applied to the specifications of wireless communication systems. In order to overcome the bottleneck, we propose an algorithm which reduce the complexity of the Viterbi decoder for STTC. The proposed Viterbi decoder for STTC apply the well-known algorithm, T-algorithm, to reduce the calculations of branch metric and reduce the complexity of the hardware design. Beside, the proposed Viterbi decoder uses the characteristics of the STTC code and hardware architecture to provide accuracy estimated SNR value. The proposed Viterbi decoder reduces the complexity and the power consumption in proportional to the SNR value. Based on the proposed Viterbi decoder, a reconfigurable MIMO STTC Viterbi decoder is designed and implemented using 0.18 um technology. The proposed decoder supports the QPSK, 8PSK and 16-QAM modulations with 4×1 and 4×4 MIMO system. The throughput of the proposed decoder achieves 59.2Mbps, 33.8Mbps, and 15.0Mbps for Q-PSK, 8-PSK, and 16-QAM modulations, respectively.
Chen, Yan-Tong, and 陳彥同. "An Integrated Message-Passing Detector and Decoder for Polar-Coded Massive MIMO Systems." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/00784071685577586836.
Повний текст джерела國立交通大學
電子研究所
105
A 1.34mm2 40nm CMOS soft-output message-passing detector and bidirectional polar decoder are designed for a QPSK massive MIMO system. The proposed reliable symbol interference cancellation technique and adaptive variance detection reduce the complexity of message passing detector (MPD) by more than 90% and generate soft log likelihood ratio (LLR) information for an ECC decoder. Exploiting a folded memory configuration saves half memory elements. An interleaved bidirectional propagation double column polar decoder is proposed to reduce the total latency of the whole decoding procedure. This work presents the first integration of an MPD and a polar decoder, delivering a throughput of 7.61Gb/s for massive MIMO systems. A soft-output MPD, which is essential to maximize channel capacity, is proposed. Compared to previous solutions, the proposed MPD achieves a 6.9 higher throughput with 49% less energy, despite the soft outputs. The proposed bidirectional polar decoder achieves a 1.35 increase in throughput with comparable energy inputs.
Sung, Chih-Sheng, and 宋志晟. "A Complex K-Best Sphere Decoder with Efficient Search Design for MIMO Systems." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/23930620613307534003.
Повний текст джерела國立交通大學
電信工程系所
97
In wireless communication systems, multiple-input and multiple-output (MIMO) technology offers significant increases in data rate and link range without additional bandwidth or transmit power. However, the design of high performance and low complexity receivers for MIMO systems is a challenging task. The maximum-likelihood (ML) detection is the optimal detection scheme but its complexity grows exponentially with the number of transmit antennas. The sphere decoding algorithm (SDA) achieves the ML performance with reduced complexity. Nevertheless, the throughput of the conventional SDA is not stable. The K-best SDA which keeps only K-best candidates at each layer for the search of next layer is guaranteed to have a stable throughput. However, to achieve a near-ML performance, the value of K should be sufficiently large. Besides, applying a sorting algorithm to find K-best candidates at each layer requires a large amount of memory access. In this thesis, we propose a complex K-best sphere decoder with an efficient search architecture. The proposed K-best sphere decoder significantly reduces the sorting complexity. We also provide the hardware architecture of the proposed complex candidate search method. It is demonstrated through analysis and simulations that the proposed K-best sphere decoder achieves a near-ML performance without requiring a large value of K.
Yeh, Che-hung, and 葉哲宏. "Joint LDPC Decoder and Channel Estimator for MIMO-OFDM Systems in Fast Fading Channel." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/77552901953575219516.
Повний текст джерела國立中正大學
通訊工程研究所
95
Multiple input multiple output- orthogonal frequency division multiplexing (MIMO-OFDM) that is a highly efficient data transmission system does not increase any transmission power or bandwidth to improve the channel capacity. For exploiting the space, time and frequency diversity, the low density parity-check (LDPC) is used as a channel coding with a built-in interleaver. We used suboptimal soft demapping algorithms, linear minimum mean square error- soft interference cancellation (LMMSE-SIC), to reduce computational complexity caused a large constellation size and a lot of transmission antennas in the receiver. In this thesis a jointed LDPC decoder and channel estimator algorithm was proposed. The algorithms applied soft bits information of LDPC to avoid estimate errors in low bits reliability during the demapping process. Finally, we used time domain channel correlation to enhance the accuracy of estimates. Computer simulations under fast fading conditions and normalized Doppler frequency 0.01 show that performance of the proposed channel estimation algorithms are 0.12 dB worse than perfect channel estimation algorithms as packet error rate is 0.01.
Huang, Li-Wen, and 黃立文. "An Interference Alignment Approach to Joint Precoder and Decoder Designs over Multiuser MIMO Interference Channels." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/75405225315804070083.
Повний текст джерела國立中央大學
通訊工程研究所
100
In multiuser interference channels, each transmitter desires to communicate its data to the intended receiver, and the multiuser interference will cause severe performance degradation on the sum rate performance if the interference signals are not appropriately mitigated. Recently, the idea of interference alignment has been emerged to utilize the spatial dimension offered by multiple antennas to overcome the interference problem and achieve the maximum sum rate performance. Although there have been some interference alignment approaches for designing precoders and decoders in recent literatures, they do not consider the desired signal strength from one transmitter to the intended receiver and the noise effect. In some cases, users may have the extremely poor SINR performance even if users’ interference signals are all appropriately aligned. Toward this end, this thesis proposes a novel iterative interference alignment approach which jointly designs the precoder and the decoder by maximizing the worst signal-to-interference and noise ratio (SINR) among users with multiple antennas. In fact, the considered optimization problem is non-convex. Based on the Karush-Kuhn-Tucker (K.K.T.) conditions, we first derive the optimality condition for designing the decoder, and propose three methods, named as bisection approach, lower bound approximation approach and SINR approximation approach, to achieve the optimal solution. For the precoder designs, we resort to the semidefinite programming (SDP) and rank relaxation techniques to transform the optimization problem into a convex form to obtain the optimal solution. Numerical results reveal that our proposed algorithms perform much better than the two existing algorithms in [1] and [2] in the generalized multiuser multi-input multi-output (MIMO) interference channels.
Botha, P. R. (Philippus Rudolph). "Iterative decoding of space-time-frequency block coded mimo concatenated with LDPH codes." Diss., 2013. http://hdl.handle.net/2263/33344.
Повний текст джерелаDissertation (MEng)--University of Pretoria, 2013.
gm2014
Electrical, Electronic and Computer Engineering
unrestricted
Louw, Daniel Johannes. "Non-binary LDPC coded STF-MIMO-OFDM with an iterative joint receiver structure." Diss., 2010. http://hdl.handle.net/2263/28061.
Повний текст джерелаDissertation (MEng)--University of Pretoria, 2010.
Electrical, Electronic and Computer Engineering
unrestricted
Al-Quwaiee, Hessa. "Bidirectional Fano Algorithm for Lattice Coded MIMO Channels." Thesis, 2013. http://hdl.handle.net/10754/292300.
Повний текст джерелаAli, Konpal S. "On Lattice Sequential Decoding for Large MIMO Systems." Thesis, 2014. http://hdl.handle.net/10754/316732.
Повний текст джерелаJenkal, Ravi S. "Architectures and design methodology for energy efficient MIMO decoders." 2008. http://www.lib.ncsu.edu/theses/available/etd-11062008-130200/unrestricted/etd.pdf.
Повний текст джерелаBen, Atitallah Ismail. "High-Dimensional Analysis of Convex Optimization-Based Massive MIMO Decoders." Thesis, 2017. http://hdl.handle.net/10754/623468.
Повний текст джерелаNatarajan, Lakshmi Prasad. "Low-Complexity Decoding and Construction of Space-Time Block Codes." Thesis, 2013. http://etd.iisc.ernet.in/2005/3372.
Повний текст джерелаLin, Bo-Yan, and 林帛諺. "Implementation and Study of Sphere Decoders on DSP-Based MIMO Platform." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/bq53du.
Повний текст джерела國立交通大學
電子工程系所
96
The sphere decoding algorithm can achieve the BER performance of the brute-force decoding method with lower complexity. In this thesis, we implement a sphere decoder in a Digital Signal Processor (DSP) based Multi-Input Multi-Output (MIMO) platform. We analyze the fixed point effect, different QR decomposition algorithms, and propose a hardware structure which enables the Quixote DSP board achieve higher data rate. Finally, we derive the equations of different types of space-time-frequency codes in the MIMO-OFDM system and find that they can be decode by the sphere decoder.
Jithamithra, G. R. "Space-Time Block Codes With Low Sphere-Decoding Complexity." Thesis, 2013. http://etd.iisc.ernet.in/handle/2005/2612.
Повний текст джерелаAbediseid, Walid. "Efficient Lattice Decoders for the Linear Gaussian Vector Channel: Performance & Complexity Analysis." Thesis, 2011. http://hdl.handle.net/10012/6271.
Повний текст джерела