We propose a simple 2/3 modulation code for multi-level holographic data storage (HDS). HDS is a promising method for the optical data storage system. However, two-dimensional (2D) inter-symbol interference (ISI) and ...
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We propose a simple 2/3 modulation code for multi-level holographic data storage (HDS). HDS is a promising method for the optical data storage system. However, two-dimensional (2D) inter-symbol interference (ISI) and inter-page interference (IPI) are weaknesses of HDS systems. Moreover, if multi-level symbols are stored, such systems are more vulnerable to errors. A modulation code can be used to alleviate these problems. Therefore, we introduce a simple 2/3 modulation code for multi-level HDS systems, which is simple and mitigates 2D ISI patterns. (c) 2013 The Japan Society of Applied Physics
Labelling diversity has appeared to be an efficient method to improve the performance of bit-interleaved space-time coded modulation with iterative decoding. It consisists in applying two different labelling maps with...
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Labelling diversity has appeared to be an efficient method to improve the performance of bit-interleaved space-time coded modulation with iterative decoding. It consisists in applying two different labelling maps within two spacial streams of the transmitter, which improves the benefits derived from multi-antenna transmission. This reported work reveals a cardinal rule the two labellings must obey to become the optimal pair for labelling diversity purposes. It is concluded from results of a generalised binary switching optimisation algorithm, delivered herein, and from distance spectrum analysis.
A framework is proposed that allows for a joint description and optimization of both binary polar coding and 2(m)-ary digital pulse-amplitude modulation (PAM) schemes. For the latter, the multilevel coding (MLC) appro...
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A framework is proposed that allows for a joint description and optimization of both binary polar coding and 2(m)-ary digital pulse-amplitude modulation (PAM) schemes. For the latter, the multilevel coding (MLC) approach as well as bit-interleaved coded modulation (BICM) are considered. The conceptual equivalence of polar coding and multilevel coding is covered in detail. Based on an alternative characterization of the channel polarization phenomenon, rules for the optimum choice of the labeling in coded modulation schemes employing polar codes are developed. Simulation results regarding the error performance of the proposed schemes on the AWGN channel are included.
In most modern wireless systems, adaptive modulation and channel coding is applied to achieve a high spectral efficiency. Hence, suitable receivers need to support a large variety of modulation and channel coding sche...
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ISBN:
(纸本)9781467331227
In most modern wireless systems, adaptive modulation and channel coding is applied to achieve a high spectral efficiency. Hence, suitable receivers need to support a large variety of modulation and channel coding schemes (MCS) while maintaining a low complexity. The performance and complexity of a multi-dimensional factor-graph based (MD-GSIR) framework for iterative joint channel estimation and data detection is investigated for the application of adaptive modulation and coding in an LTE environment. Three detection algorithms within the MD-GSIR framework are investigated and a novel tree-based detection is proposed. The versatile structure of the MD-GSIR concept offers a flexible trade-off between computational complexity and performance. Furthermore, the message exchange is adapted to support the irregular training structure which may occur in adaptive environments.
In the wireless communication systems, the bandwidth is usually variable because of the dynamic channel. Although the optimal number of subpackets and AMC scheme has been proposed recently, it is limited to the fixed ...
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ISBN:
(纸本)9781424453023
In the wireless communication systems, the bandwidth is usually variable because of the dynamic channel. Although the optimal number of subpackets and AMC scheme has been proposed recently, it is limited to the fixed bandwidth. In this paper, a cross-layer design named AMC-SPS-SVB which combines AMC and ASPS with SR-ARQ is proposed to maximize the throughput of the system in a dynamic channel with the variable bandwidth. Curve fitting is applied here to give out approximate expressions of bit error rate under given modulation and coding schemes. General closed-form expressions of effective spectrum efficiency and optimal subpacket size under given modulation and coding schemes for our algorithm are presented. Furthermore, an efficient method is provided to find the optimal AMC and subpacket size. Numerical results show that the proposed algorithm improves the throughput of the system and works well with the variable bandwidth.
In this paper, we consider a broadcast channel in spectrum-sharing networks, where the base station schedules licensed primary users (PUs) and cognitive secondary users (SUs) simultaneously. Based on such a framework,...
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ISBN:
(纸本)9781467331227
In this paper, we consider a broadcast channel in spectrum-sharing networks, where the base station schedules licensed primary users (PUs) and cognitive secondary users (SUs) simultaneously. Based on such a framework, we present a transmission strategy in the light of dirty paper coding. In order to promise the PUs' quality of service (QoS) in the broadcasting, the base station chooses codewords for the users by taking into account that the codewords pertaining to SUs can be pre-subtracted from those pertaining to PUs as if there were no interference from the secondary's data to the primary's data. For the purpose of performance evaluation, by taking capacity behavior and bit error rate (BER) as metrics, we study the achievable data rate regions for both types of users with the introduced design, and analyze the BER performance in corresponding systems implemented with hierarchical modulation. Numerical results substantiate that with flexible management of the spectrum resources, our proposed scheme provides more communication opportunities for SUs while maintaining PUs' QoS at an acceptable level.
This paper considers ad hoc networks that use the combination of coded continuous-phase frequency-shift keying (CPFSK) and frequency-hopping multiple access. Although CPFSK has a compact spectrum, some of the signal p...
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ISBN:
(纸本)9781467331227
This paper considers ad hoc networks that use the combination of coded continuous-phase frequency-shift keying (CPFSK) and frequency-hopping multiple access. Although CPFSK has a compact spectrum, some of the signal power inevitably splatters into adjacent frequency channels, thereby causing adjacent-channel interference (ACI). The amount of ACI is controlled by setting the fractional in-band power;i.e., the fraction of the signal power that lies within the band of each frequency channel. While this quantity is often selected arbitrarily, a tradeoff is involved in the choice. This paper presents a new analysis of frequency-hopping ad hoc networks that carefully incorporates the effect of ACI. The analysis accounts for the shadowing, Nakagami fading, CPFSK modulation index, code rate, number of frequency channels, fractional in-band power, and spatial distribution of the interfering mobiles. Expressions are presented for both outage probability and transmission capacity. With the objective of maximizing the transmission capacity, the optimal fractional in-band power that should be contained in each frequency channel is identified.
Bit Error Rate (BER) is a key parameter used to evaluate the performance of radio communication systems. In this paper, a realistic BER of radio MRC diversity systems is predicted based on the Multi-Resolution Frequen...
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ISBN:
(纸本)9781467359399;9781467359382
Bit Error Rate (BER) is a key parameter used to evaluate the performance of radio communication systems. In this paper, a realistic BER of radio MRC diversity systems is predicted based on the Multi-Resolution Frequency Domain Par Flow (MR-FDPF) model. The prediction takes into account the correlations among diversity branches and makes no assumptions of the correlation model. The predicted realistic BER for MRC diversity systems can be very useful to many wireless applications, such as, adaptive modulation and coding (AMC) scheme, or optimal power allocation.
In this paper, we propose the multi-level physical-layer network coding (MPLNC) for two-way relay channels (TWRC) to optimize the relay performance. In the proposed MPLNC scheme, each source node involves multiple lin...
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ISBN:
(纸本)9781467359399;9781467359382
In this paper, we propose the multi-level physical-layer network coding (MPLNC) for two-way relay channels (TWRC) to optimize the relay performance. In the proposed MPLNC scheme, each source node involves multiple linear binary codes for encoding, one per modulation level. The relay node receives these streams of signals and attempts to decode superimposed network codewords at each modulation level. We first derive the constellation constrained capacity for TWRC, and then prove that MPLNC can approach the channel capacity if and only if binary code rates are properly chosen for both source nodes. Furthermore, to facilitate practical implementation MPLNC, the design criteria for the proposed MPLNC scheme is investigated, which includes the rate design rule, the decoding order design rule and the labeling strategy design rule. Also discussed is the relation between MPLNC and bit-interleaved coded modulation (BICM)-based PLNC. Our analysis and simulation results indicate that MPLNC has a significant performance advantage in comparison to the BICM-based PLNC.
Existing works in image compressed sensing (CS) often focus on improving the rate-distortion sensing performance but have less consideration of the effect of channel errors on the transmission of CS measurements. This...
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ISBN:
(纸本)9781467362382
Existing works in image compressed sensing (CS) often focus on improving the rate-distortion sensing performance but have less consideration of the effect of channel errors on the transmission of CS measurements. This paper explores how the transmission channel errors affect the PSNR performance of the quantized sensing measurements and then increases the resistance of the transmitted data to the noisy channel. We show that the multi-scale block based compressed sensing (MSBCS) using quantization with differential phase code modulation (DPCM), though achieves compression efficiency higher than the regular scalar quantization-based CS, is more vulnerable to channel errors. To improve the error resistance, a method of optimized energy allocation across bit-layers in quantized measurements is presented, which leads to a large PSNR performance improvement for CS data transmission in wireless environment.
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