Reduction of ML decoding complexity for MIMO Sphere Decoding, QOSTBC, and OSTBC

Azzam, L.; Ayanoğlu, Ender

doi:10.1109/ita.2008.4601014

Cited by 14 publications

(10 citation statements)

References 25 publications

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“…STBC adalah teknik yang digunakan dalam komunikasi wireless untuk mengirimkan salinan dari sebuah aliran data di sejumlah antenna dan memanfaatkan berbagai variasi data yang diterima dan untuk meningkatkan kehandalan transfer data. Analisa performansi [7], tetapi terfokus hanya pada proses decoding nya saja. Dalam penelitian ini diajukan sebuah analisa perbandingan antara modulasi BPSK dan QPSK dengan digabungkan dengan teknik diversity OSTBC dengan rate ½ dan dengan daya transmisi yang berbeda-beda.…”

Section: Pendahuluanunclassified

PERBANDINGAN KINERJA OSTBC (Orthogonal Space Time Block Code) DENGAN RATE ½ MENGGUNAKAN MODULASI BPSK & QPSK

Perdana

2017

Media Komunikasi Teknologi

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The wireless communication system is a well known and a standard technology. However, the system performance is highly dependent on the channel fading between transmitter and receiver. Therefore Keywords : MIMO, OSTBC, BER ABSTRAKSistem komunikasi tanpa kabel merupakan teknologi yang sudah dikenal dan sudah umum digunakan. Namun, kinerja dari sistem komunikasi tanpa kabel ini sangat bergantung oleh keadaan kanal fading antara transmitter dan receiver. Untuk mengurangi efek fading muncul teknik transmit diversity, salah satunya yaitu teknik MIMO (Multiple Input Multiple Output).Salah satu teknik transmit diversity adalah Orthogonal Space Time Block Code (OSTBC). OSTBC merupakan teknik pengkodean kanal transmisi dengan antena pemancar dan penerima lebih dari satu. Prinsip dari OSTBC yaitu mengirimkan beberapa salinan sinyal informasi dari sebuah aliran data di sejumlah antena, sehingga ada beberapa salinan data yang diterima lebih baik dari pada yang lain. Dengan dipadukan dengan modulasi BPSK dipadatkan nilai Bit Error Rate (BER) sebesar 10-3 pada Signal to Noise Ratio (SNR) 5 dB, sedangkan ketika dipadukan dengan modulasi QPSK didapatkan nilai BER sebesar 10-3 pada SNR 7 dB. Kata Kunci : MIMO, OSTBC, BER PENDAHULUANSaat ini, sistem komunikasi wireless merupakan teknologi yang sudah dikenal dan sudah umum digunakan. Namun, kinerja dari sistem komunikasi wirelesssangat bergantung oleh keadaan kanal antara transmitter dan receiver yang rentan terhadap fading. Untuk mengurangi efek fading muncul teknik transmit diversity, salah satunya yaitu teknik MIMO (Multiple Input Multiple Output) [1]. Dimana MIMO merupakan penggunaan multi antenna pada sisi transmitter dan receiveryang diharapkan mampu memperkecil efek dari fading.Dalam penelitian Alamouti -yang dikenal dengan Space-time Diversity, diketahui bahwa penggunaan skema diversity dengan satu antenna transmitter dan dua antenna receiver dapat lebih mengoptimalkan komunikasi wireless karena dapat memperbaiki performansi BER.Penelitian selanjutnya yang dilakukan oleh V. Tarokh mengemukakan skema STBC (Space-Time Block Coding) yang memiliki performa lebih baik dibandingkan dengan penelitian Alamouti [2]. Penelitian ini melakukan proses transmisi melalui kanal Rayleigh fading serta antenna transmitter lebih dari satu. STBC adalah teknik yang digunakan dalam komunikasi wireless untuk mengirimkan salinan dari sebuah aliran data di sejumlah antenna dan memanfaatkan berbagai variasi data yang diterima dan untuk meningkatkan kehandalan transfer data. Analisa performansi Artikel ini disebarluaskan di bawah lisensi CC BY-NC-SA (https://creativecommons.org/licenses/by-nc-sa/4.0/ )

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Section: Pendahuluanunclassified

PERBANDINGAN KINERJA OSTBC (Orthogonal Space Time Block Code) DENGAN RATE ½ MENGGUNAKAN MODULASI BPSK & QPSK

Perdana

2017

Media Komunikasi Teknologi

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“…The full K-best finds the transmitted symbol x by solving (2). In this equation, N denotes W N possible sets of the transmitted symbol vector x, and z = Q H y.…”

Section: Channel Model and Full K-best Algorithmmentioning

confidence: 99%

“…Among these, it is well known that the MLD is the optimal approach in terms of bit error rate (BER) performance. However, its complexity increases exponentially with the number of constellation points of the modulation and with the number of spatial streams [2]. Several researches on suboptimal MLD algorithms, especially on the full *Correspondence: hong@dsp.cse.kyutech.ac.jp 1 Kyushu Institute of Technology, 680-4 Kawazu Iizuka, Fukuoka 820-8502, Japan Full list of author information is available at the end of the article K-best, have been done instead.…”

Section: Introductionmentioning

confidence: 99%

Algorithm and hardware design of a 2D sorter-based K-best MIMO decoder

Tran

Nagao²,

Ochi

2014

J Wireless Com Network

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In the field of multiple input multiple output (MIMO) decoder, K-best has been well investigated because it guarantees an SNR-independent fixed-throughput with a performance close to the optimal maximum likelihood detection (MLD). However, the complexity of its expansion and sorting tasks is significantly affected by the constellation size W. In this paper, we propose an algorithm and hardware design of a 2D sorter-based K-best MIMO decoder whose complexity is negligibly affected by W. The main novelties of the algorithm are the following: (1) Direct expansion and parent node grouping ideas are proposed for reducing the expansion task's complexity.(2) Two-dimensional (2D) sorter is proposed for simplifying the sorting task. The hardware design of the decoder supports up to 256-QAM modulation, which aims to apply into 4 × 4 MIMO 802.11n and 11ac systems. The paper shows that the proposed decoder outperforms the Bell Labs layered space-time (BLAST) minimum mean square error (MMSE) and lattice-reduction aided (LRA) MMSE, and is close to the full K-best in terms of bit error rate (BER) performance. The hardware design of the decoder is synthesized in application specific integrated circuit (ASIC) and compared with the previous works. As a result, it achieves the highest throughput (up to 2.7 Gbps), consumes the least power (56 mW), obtains the best hardware efficiency (15.2 Mbps/Kgate), and has the shortest latency (0.07 μs).

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“…K-best MLD only selects K candidates of the transmitted symbol vector at each stage as opposed to the full candidate search of MLD [3] - [5]. However, K-best MLD is still very hard to implement in hardware when the number of constellation points is high such as 256 QAM.…”

Section: Introductionmentioning

confidence: 99%

A design of low complex log likelihood ratio for MIMO decoder using the bit shift

Hongyo

Tran

Lanante

et al. 2014

2014 IEEE Asia Pacific Conference on Circuits and Systems (APCCAS)

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In Multiple Input Multiple Output (MIMO) decoders, soft decision in the form of Log Likelihood Ratio (LLR) is often used to enhance the error correction probability of the Forward Error Correction (FEC). In order to compute the LLR, the zero's probability and the one's probability of an information bit must be known. In case of using the K-best maximum likelihood detection (MLD), only a subset of constellation nodes is considered for computing the LLR. Which results in cases where values of information bit corresponding to the selected nodes are all zero (or one). In those cases, the one's (or zero's) probability cannot be found. In other words, conventional method calculates LLR approximation with maximum value calculation, but it is high complex. In this paper, we propose a design of MIMO decoder using LLR approximation with low complexity achieved by approximating the maximum value calculation. Our proposed method approximates LLR using the bit shift of the minimum value already calculated. The Bit Error Rate (BER) performance of the IEEE 802.11ac system and ASIC synthesis results of the 4×4 K-best MLD when using these two methods are shown and analyzed. As a result, our proposed design can reduce 27% of the circuit size and the power consumption while maintaining the BER performance of the conventional method.

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Reduction of ML decoding complexity for MIMO Sphere Decoding, QOSTBC, and OSTBC

Cited by 14 publications

References 25 publications

PERBANDINGAN KINERJA OSTBC (Orthogonal Space Time Block Code) DENGAN RATE ½ MENGGUNAKAN MODULASI BPSK & QPSK

PERBANDINGAN KINERJA OSTBC (Orthogonal Space Time Block Code) DENGAN RATE ½ MENGGUNAKAN MODULASI BPSK & QPSK

Algorithm and hardware design of a 2D sorter-based K-best MIMO decoder

A design of low complex log likelihood ratio for MIMO decoder using the bit shift

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