In this invited paper, we describe an adaptive nonbinary LDPC coded modulation scheme suitable for high-speed optical transport networks, which is based on irregular quasi-cyclic-LDPC codes derived from pairwise balan...
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ISBN:
(纸本)9781479950485
In this invited paper, we describe an adaptive nonbinary LDPC coded modulation scheme suitable for high-speed optical transport networks, which is based on irregular quasi-cyclic-LDPC codes derived from pairwise balanced designs, providing excellent coding gains.
A promising method for tomography and step height measurement is proposed, which combines the high sensitivity of the frequency-shifted feedback laser and the axial positioning ability of confocal microscopy. By demod...
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A promising method for tomography and step height measurement is proposed, which combines the high sensitivity of the frequency-shifted feedback laser and the axial positioning ability of confocal microscopy. By demodulating the feedback-induced intensity modulation signals, the obtained amplitude and phase information are used to respectively determine the coarse and fine measurement of the samples. Imaging the micro devices and biological samples by the demodulated amplitude, this approach is proved to be able to achieve the cross-sectional image in highly scattered mediums. And then the successful height measurement of nano-step on a glass-substrate grating by combination of both amplitude and phase information indicates its axial high resolution (better than 2 nm) in a non-ambiguous range of about ten microns.
A new coded modulation technique, termed bit-cooperative coded modulation (BCCM), is proposed in this paper. By introducing a pseudo-random sequence at the transmitter to systematic low-density parity-check (LDPC) cod...
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ISBN:
(纸本)9781467359399;9781467359382
A new coded modulation technique, termed bit-cooperative coded modulation (BCCM), is proposed in this paper. By introducing a pseudo-random sequence at the transmitter to systematic low-density parity-check (LDPC) codes, the receiver enjoys the benefits of increased minimum Euclidean distance and the Hamming distance when applying this side-information at the receiver. In particular, we propose a new constellation mapping principle to take advantage of the side information. Our analysis indicates that the side information makes the regular LDPC code irregular, with irregularity specified by the check node degree distribution, which allows the density evolution approach to be used to design and optimize the regular LDPC code for the BCCM. We then analytically derive the constellation constrained capacity for the BCCM. The performance of the LDPC-coded BCCM on AWGN channels and Rayleigh fading channels is analyzed using the density evolution and extensive simulations.
We report the experimental transmission of 4-D coded modulation formats based on set-partitioning of two 16QAM 2-D constellations. Using Nyquist-pulse-shaping, 32SP-DP-16QAM and 128SP-DP-16QAM signals are transmitted ...
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ISBN:
(纸本)9781557529626;9781479904570
We report the experimental transmission of 4-D coded modulation formats based on set-partitioning of two 16QAM 2-D constellations. Using Nyquist-pulse-shaping, 32SP-DP-16QAM and 128SP-DP-16QAM signals are transmitted over long-haul distance and compared with PDM-16QAM.
In this contribution we compare the performance of polarization-division multiplexed quadrature phase-shift keying (PDM-QPSK) signals and 6-ary polarization-shift keying (6PolSK)-QPSK signals in wavelength-division mu...
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ISBN:
(纸本)9783800735037
In this contribution we compare the performance of polarization-division multiplexed quadrature phase-shift keying (PDM-QPSK) signals and 6-ary polarization-shift keying (6PolSK)-QPSK signals in wavelength-division multiplexing (WDM) experiments over up to 5280 km G.652 standard single-mode fiber (SSMF). Both modulation formats are compared at the same symbol rate of 28 GBd. Due to its higher spectral efficiency 6PolSK-QPSK then transmits 126 Gb/s compared to 112 Gb/s when using PDM-QPSK. This enables application of stronger forward error correction (FEC) codes with larger overhead. The achievable gain in maximum reach by application of an additional inner Reed-Solomon FEC code is quantified in transmission experiments. Furthermore, the interaction between FEC and digital compensation of intra-channel nonlinear effects is discussed.
A 4-code code switching keying (CSK) modulation scheme was proposed. It can scramble the optical codes (OC) bit by bit to defeat the differential eavesdropping toward the upstream of the optical code division multiple...
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ISBN:
(纸本)9781479905607
A 4-code code switching keying (CSK) modulation scheme was proposed. It can scramble the optical codes (OC) bit by bit to defeat the differential eavesdropping toward the upstream of the optical code division multiple access (OCDMA) network. The transmission and security test results for the 4-code CSK-OCDMA system at a data rate of 2.5 Gb/s were presented in this paper. It verified that the CSK-OCDMA system can provide a security and error free transmission service in an access network. The proposed system has a simple framework, enhanced security and especially asynchronous transmission compared to other CSK-OCDMA systems against eavesdropping.
This paper reports on the design and performance of a new Variable Coded modulation (VCM) system. This VCM system comprises eight of NASA's recommended codes from the Consultative Committee for Space Data Systems ...
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ISBN:
(纸本)9781467318129
This paper reports on the design and performance of a new Variable Coded modulation (VCM) system. This VCM system comprises eight of NASA's recommended codes from the Consultative Committee for Space Data Systems (CCSDS) standards, including four turbo and four AR4JA/C2 low-density parity-check codes, together with six modulations types (BPSK, QPSK, 8-PSK, 16-APSK, 32-APSK, 64-APSK). The signaling protocol for the transmission mode is based on a CCSDS recommendation. The coded modulation may be dynamically chosen, block to block, to optimize throughput. A novel aspect of the VCM design is that each operating mode has a unique number of symbols in its frame. This enables the receiver to identify the code and modulation simply from the number of symbols occurring between the dedicated frame markers which occur between frames, without having to explicitly transmit a signal to identify the operating mode. This concept allows for a limitless selection of modes and low complexity design. The paper describes a MATLAB end-to-end simulation consisting of random data generation, encoding the data, modulation of the data, additive white Gaussian noise for channel simulation, frame marker identification, coded modulation mode extraction, demodulation, and decoding. Achievable error rates and total throughput are recorded. This simulation can be applied to any link budget that describes the signal to noise ratio over time and can selectively use all or some of the supported coded modulation modes. The simulations show that for a representative low-Earth orbit satellite which encounters a 15 dB variation of symbol SNRs in a 10 minute pass, VCM doubles the achievable throughput, compared to the optimal fixed-mode communication. This simulation shows that VCM is a major and practical method for communicating high data volumes from space.
Assuming a logarithmic rate model for SISO (Single-Input Single-Output) systems, the information theoretic capacity under scheduling algorithms exploiting multiuser diversity in wireless networks has been studied so f...
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Assuming a logarithmic rate model for SISO (Single-Input Single-Output) systems, the information theoretic capacity under scheduling algorithms exploiting multiuser diversity in wireless networks has been studied so far. However, in many cases, the throughput achieved in real wireless networks is very different from (and is much less than) the information theoretic capacity obtained under the assumption of the logarithmic rate model, and the rate functions in real wireless networks are very different from the logarithmic rate model. Hence, to examine the usefulness of the scheduling algorithms exploiting multiuser diversity in real wireless networks, we should study the throughput performance under more realistic rate function model rather than the information theoretic capacity under the logarithmic rate model. In this paper, we consider a wireless network where QPF (Quantized Proportional Fair) scheduling and AMC (adaptive modulation and coding) scheme are employed. Assuming a realistic rate function of AMC, we then analyze the throughput performance under the QPF scheduling with the AMC scheme. We also provide numerical results to investigate the usefulness of the QPF scheduling with the AMC scheme.
The Adaptive modulation and coding (AMC) scheme which handles user's mobility issue plays a significant role to improve the desired quality of service in high Speed Downlink Packet Access (HSDPA) networks. We deve...
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The Adaptive modulation and coding (AMC) scheme which handles user's mobility issue plays a significant role to improve the desired quality of service in high Speed Downlink Packet Access (HSDPA) networks. We develop a resource allocation which maintains constant bit rate for real-time (RT) and non-real-time (NRT) calls independently of the user position in the cell. We present analytical results relating to user performance in terms of blocking and dropping probabilities, and the results relating to the system performance in term of total throughput. We propose a call admission control scheme to derive a good trad-off between the blocking and dropping probabilities, and the choice of scheduling that efficiently utilizes the available resources.
In this paper we develop a technique for adaptive configuration of multi-antenna systems including modulation, coding, and the multi-antenna scheme without channel state information at the transmitter (CSIT) and with ...
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In this paper we develop a technique for adaptive configuration of multi-antenna systems including modulation, coding, and the multi-antenna scheme without channel state information at the transmitter (CSIT) and with minimal feedback. Using a combination of theoretical and simulation-based models, we develop and verify a set of multi-antenna-scheme specific distance metrics for adaptation. Further, we integrate these MIMO distance metrics with standard distance metrics for adaptive modulation and coding (AMC). We show that with these simple metrics the adaptive scheme can achieve performance that is close to channel capacity and within a fraction of a dB of the best throughput achievable for the transmissions modes considered. The focus of this work is adaptation for a fixed BER while maximizing the spectral efficiency using minimal feedback.
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