arXiv subjects

Jiaru Lin

Publications and source records attributed to Jiaru Lin.

23 records · Page 2Linked to original sources

arXiv2014

Space-Time Polar Coded Modulation

The polar codes are proven to be capacity-achieving and are shown to have equivalent or even better finite-length performance than the turbo/LDPC codes under some improved decoding algorithms over the additive white Gaussian noise (AWGN) channels. Polar coding is based on the so-called channel polarization phenomenon induced by a transform over the underlying binary-input channel. The channel polarization is found to be universal in many signal processing problems and has been applied to the coded modulation schemes. In this paper, the channel polarization is further extended to the multiple antenna transmission following a multilevel coding principle. The multiple-input multile-output (MIMO) channel under quadrature amplitude modulation (QAM) are transformed into a series of synthesized binary-input channels under a three-stage channel transform. Based on this generalized channel polarization, the proposed space-time polar coded modulation (STPCM) scheme allows a joint optimization of the binary polar coding, modulation and MIMO transmission. In addition, a practical solution of polar code construction over the fading channels is also provided, where the fading channels are approximated by an AWGN channel which shares the same capacity with the original. The simulations over the MIMO channel with uncorrelated Rayleigh fast fading show that the proposed STPCM scheme can outperform the bit-interleaved turbo coded scheme in all the simulated cases, where the latter is adopted in many existing communication systems.

cs.IT↗

arXiv2014

Polar Coded HARQ Scheme with Chase Combining

A hybrid automatic repeat request scheme with Chase combing (HARQ-CC) of polar codes is proposed. The existing analysis tools of the underlying rate-compatible punctured polar (RCPP) codes for additive white Gaussian noise (AWGN) channels are extended to Rayleigh fading channels. Then, an approximation bound of the throughput efficiency for the polar coded HARQ-CC scheme is derived. Utilizing this bound, the parameter configurations of the proposed scheme can be optimized. Simulation results show that, the proposed HARQ-CC scheme under a low-complexity SC decoding is only about $1.0$dB away from the existing schemes with incremental redundancy (\mbox{HARQ-IR}). Compared with the polar coded \mbox{HARQ-IR} scheme, the proposed HARQ-CC scheme requires less retransmissions and has the advantage of good compatibility to other communication techniques.

cs.IT↗

arXiv2013

Low-Complexity Sphere Decoding of Polar Codes based on Optimum Path Metric

Sphere decoding (SD) of polar codes is an efficient method to achieve the error performance of maximum likelihood (ML) decoding. But the complexity of the conventional sphere decoder is still high, where the candidates in a target sphere are enumerated and the radius is decreased gradually until no available candidate is in the sphere. In order to reduce the complexity of SD, a stack SD (SSD) algorithm with an efficient enumeration is proposed in this paper. Based on a novel path metric, SSD can effectively narrow the search range when enumerating the candidates within a sphere. The proposed metric follows an exact ML rule and takes the full usage of the whole received sequence. Furthermore, another very simple metric is provided as an approximation of the ML metric in the high signal-to-noise ratio regime. For short polar codes, simulation results over the additive white Gaussian noise channels show that the complexity of SSD based on the proposed metrics is up to 100 times lower than that of the conventional SD.

cs.IT↗

arXiv2013

Polar Coded Modulation with Optimal Constellation Labeling

A practical $2^m$-ary polar coded modulation (PCM) scheme with optimal constellation labeling is proposed. To efficiently find the optimal labeling rule, the search space is reduced by exploiting the symmetry properties of the channels. Simulation results show that the proposed PCM scheme can outperform the bit-interleaved turbo coded modulation scheme used in the WCDMA (Wideband Code Division Multiple Access) mobile communication systems by up to 1.5dB.

cs.IT↗

arXiv2013

A Hybrid ARQ Scheme Based on Polar Codes

A hybrid automatic repeat request (HARQ) scheme based on a novel class of rate-compatible polar (\mbox{RCP}) codes are proposed. The RCP codes are constructed by performing punctures and repetitions on the conventional polar codes. Simulation results over binary-input additive white Gaussian noise channels (BAWGNCs) show that, using a low-complexity successive cancellation (SC) decoder, the proposed HARQ scheme performs as well as the existing schemes based on turbo codes and low-density parity-check (LDPC) codes. The proposed transmission scheme is only about 1.0-1.5dB away from the channel capacity with the information block length of 1024 bits.

cs.IT↗