Performance Analysis and Design Optimization of LDPC-Coded MIMO OFDM Systems

Lu, Bin; Yue, Guosen; Wang, Xiaodong

doi:10.1109/tsp.2003.820991

Cited by 146 publications

(48 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The digital image samples of each RGB components are multiplexed serially and encoded as a block of k input bits (21600) in the LDPC encoder by a rate r = k/n LDPC code. The encoder output n (43200) coded bits are interleaved and subsequently applied to the½-rated Convolutional encoder constellation Ω into a block of n/log 2 │Ω│ complex PSK/QAM modulation symbols [10]. The symbols are then fed into OFDM modulator which performs an IFFT on each OFDM block of length 64 symbols/ sub carriers followed by a parallel to serial conversion.…”

Section: System Descriptionmentioning

confidence: 99%

BER Performance Analysis of a Concatenated Low Density Parity Check Encoded OFDM System in AWGN and Fading Channels

et al. 2009

View full text Add to dashboard Cite

In this paper, we investigate the bit error rate (BER) performance of a concatenated low density parity check (LDPC) encoded orthogonal frequency-division multiplexing (OFDM) system on color image transmission. In FEC concatenated channel coding, the OFDM wireless communication system incorporates 1/2-rated convolution encoder under various digital modulations (QPSK, 8PSK, QAM, 8QAM, 16QAM and 32QAM) over an additative white gaussian noise (AWGN) and other fading (Raleigh and Rician) channels. Computer simulation results on BER demonstrate that the LDPC encoded OFDM system outperforms with QAM modulation technique as compared to other digital modulation scheme and the system is highly effective to combat inherent interferences under Rayleigh and Rician fading channels. The transmitted color image is found to have retrieved effectively under noisy and fading situations with implementation of sum-product algorithm, an effective iterative based LDPC decoding scheme. It has also been anticipated that the performance of the communication system degrades with the increasing of noise power.

show abstract

Section: System Descriptionmentioning

confidence: 99%

BER Performance Analysis of a Concatenated Low Density Parity Check Encoded OFDM System in AWGN and Fading Channels

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Since we have bit interleaving, we may assume that the probabilities of the bits that compose the symbol are independent [8], [9]. From (5), it is clear that when recalculating the bit metrics for one bit, we only need to use the a priori probabilities of the other bits in the same channel symbol.…”

Section: A Iterative Symbol-to-bit De-mapping For Mpsk Constellationsmentioning

confidence: 99%

EXIT Chart Analysis of Iterative Demodulation and Decoding of MPSK Constellations with Signal Space Diversity

Kiyani¹,

Weber

2008

JCM

View full text Add to dashboard Cite

Abstract-Bit interleaved coded modulation (BICM) schemes have been shown to increase the diversity order. This paper studies the extension of such schemes with iterative demodulation and decoding (ID) using error correcting codes coupled with rotated MPSK signal constellations with different symbol mappings and signal space diversity (SSD). Using extrinsic information transfer (EXIT) charts, an analysis of the impact of the rotation angle on the performance of the system is presented. It is shown that for a given signal constellation, labeling, error correcting code and E b /N0-value, where conventional BICM-ID system's decoding trajectory gets stuck in a Rayleigh fading channel, SSD with a well considered choice of the rotation angle allows for the convergence of iterative demodulation and decoding. Furthermore, it is shown that the proposed system can lead to a significant performance gain over BICM-ID. The optimal choice of the rotation angle for the coded system is shown to be dependent upon the signal labeling and the error correcting code being employed. Factors (degrees of freedom) that can effect the convergence behavior of the iterative demodulation and decoding of the proposed system are identified and their effect is analyzed.

show abstract

“…11 The Alamouti code essentially transforms the MIMO channel into two parallel scalar channels [ performance gain at essentially no additional computational expense compared to conventional SM. The performance improvement delivered by CoRa when used in combination with channel codes optimized for fading channels (e.g., [26], [27]), and with turbo demodulation, or suboptimal demodulation schemes, remains to be investigated. One could also envision a combination of CoRa and linear precoding.…”

Section: Discussionmentioning

confidence: 99%

Constellation randomization (CoRa) for outage performance improvement on MIMO channels

Larsson

IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.

View full text Add to dashboard Cite

Abstract-This paper studies a new concept, "constellation randomization" (CoRa), for performance improvement of transmission over quasi-static (block fading) multidimensional ("MIMO") channels with small signal constellations. The motivation behind CoRa is to reduce some of the mutual information penalty associated with the use of a finite input alphabet for signalling on a static, possibly ill-conditioned, channel. We show, both via information-theoretic considerations, and via MonteCarlo simulation of the frame-error-rate (FER) of a coded system, that CoRa can offer a lower outage probability than a conventional spatial multiplexing system that uses a fixed signal constellation. In our examples the improvement offered by CoRa is comparable to that offered by linear (complex-field) precoding. This is interesting, because the performance gain of CoRa comes at virtually no computational expense.

show abstract

Performance Analysis and Design Optimization of LDPC-Coded MIMO OFDM Systems

Cited by 146 publications

References 25 publications

BER Performance Analysis of a Concatenated Low Density Parity Check Encoded OFDM System in AWGN and Fading Channels

BER Performance Analysis of a Concatenated Low Density Parity Check Encoded OFDM System in AWGN and Fading Channels

EXIT Chart Analysis of Iterative Demodulation and Decoding of MPSK Constellations with Signal Space Diversity

Constellation randomization (CoRa) for outage performance improvement on MIMO channels

Contact Info

Product

Resources

About