In this paper a coded modulation method for the additive white Gaussian noise channel is presented which incorporates signal shaping. The scheme uses a modulation map to map bits to channel inputs. A modulation map is...
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In this paper a coded modulation method for the additive white Gaussian noise channel is presented which incorporates signal shaping. The scheme uses a modulation map to map bits to channel inputs. A modulation map is considered that has the advantage it is can easily be combined with binary error-correcting codes. The decoding strategy is a combination of bit-interleaved coded modulation and multistage decoding. The number of required decoding stages is only small compared to other multistage decoding schemes for coded modulation. It is shown that modulation maps can be designed with a constrained capacity limit very close to the capacity of the AWGN channel. When combined with low-density parity-check codes, simulation results show that a near-capacity performance is achieved for high spectral efficiencies.
An alternative design for constructing multilevel space-time codes is proposed. For a given space-time block code, we combine several component codes in conjunction with set partitioning of the expanded signal constel...
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An alternative design for constructing multilevel space-time codes is proposed. For a given space-time block code, we combine several component codes in conjunction with set partitioning of the expanded signal constellation according to the coding gain distance criterion. The error performance of an example code is compared with a traditional multilevel space-time code in computer simulation.
In this Paper, we proposed a multilevel coding scheme for 64DAPSK Modulated OFDM signals. The performance comparison with single level coding for 64QAM and 64DAPSK is given based on simulations. Simulation proved that...
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ISBN:
(纸本)9781424458516
In this Paper, we proposed a multilevel coding scheme for 64DAPSK Modulated OFDM signals. The performance comparison with single level coding for 64QAM and 64DAPSK is given based on simulations. Simulation proved that it has about 1 similar to 1.5 dB gain over different channels.
In this paper, we evaluate a multilevel coding (MLC) scheme with multi-stage decoding (MSD) designed for satellite broadcasting communications, where services with different quality of service (QoS) are desirable. A s...
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ISBN:
(纸本)9781424435746
In this paper, we evaluate a multilevel coding (MLC) scheme with multi-stage decoding (MSD) designed for satellite broadcasting communications, where services with different quality of service (QoS) are desirable. A simple Land-Mobile-Satellite (LMS) channel model is presented, based on channel states and their transitions. The instantaneous channel capacity for suburban and forest scenarios is calculated using the mutual information concept. An established transmission scheme for satellite broadcasting, which uses bit-interleaved coded modulation (BICM) with Gray mapping, is compared with the MLC scheme in terms of channel capacity and outage probability. The effect of removing a long channel interleaver in the physical layer is analyzed, showing that the MLC scheme is a good alternative to BICM for satellite broadcasting.
A bandwidth- and power-efficient modulation scheme using M-ary differential phase-shift keying (DPSK)/differential quadrature amplitude modulation (DQAM) and low-density parity-check (LDPC) codes as component codes in...
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A bandwidth- and power-efficient modulation scheme using M-ary differential phase-shift keying (DPSK)/differential quadrature amplitude modulation (DQAM) and low-density parity-check (LDPC) codes as component codes in a multilevel coding (MIX) is proposed for optical transmission systems with direct detection. An MIX scheme with 2 b/s/Hz spectral efficiency based on block-circulant component codes provides the coding gain of 12.3 dB when compared to uncoded 8-DPSK, and 8.3 dB when compared to uncoded 4-DPSK (QDPSK).
The performance of bit-interleaved coded modulation (BICM) with shaping (i.e., non-equiprobable bit probabilities) is studied. For the AWGN channel, the rates achievable with BICM and shaping are practically identical...
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In this Paper, we proposed a multilevel coding scheme for 64DAPSK Modulated OFDM signals. The performance comparison with single level coding for 64QAM and 64DAPSK is given based on simulations. Simulation proved that...
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ISBN:
(纸本)9781424458509;9781424458493
In this Paper, we proposed a multilevel coding scheme for 64DAPSK Modulated OFDM signals. The performance comparison with single level coding for 64QAM and 64DAPSK is given based on simulations. Simulation proved that it has about 1～1.5 dB gain over different channels.
In this paper, we introduce a Turbo coded modulation scheme, called multilevel turbo coded-continuous phase frequency shift keying (MLTC-CPFSK). The underlying basis of multilevel coding is to partition a signal set i...
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In this paper, we introduce a Turbo coded modulation scheme, called multilevel turbo coded-continuous phase frequency shift keying (MLTC-CPFSK). The underlying basis of multilevel coding is to partition a signal set into several levels and to encode separately each level through the respective layer of the encoder. In MLTC-CPFSK, to provide phase continuity of the signals, turbo encoder and continuous phase encoder (CPE) are serially concatenated at the last level, while all other levels consist of only a turbo encoder. Therefore, the proposed system contains multiple turbo encoder/decoder blocks in its architecture. The parallel input data sequences are encoded by our multilevel scheme and mapped to CPFSK signals. Then, for the purpose of performance analysis, these modulated signals are passed through AWGN and fading channels. At the receiver side, the input sequence of the first level is estimated by the first turbo decoder block. Subsequently, the other input sequences of other levels are computed using the estimated input bit streams of the respective previous levels. Simulation results are drawn for 4-ary CPFSK two level and 8-ary CPFSK three level turbo codes over AWGN, Rician, and Rayleigh channels for three iterations while frame sizes are chosen as 100 and 1024. It is concluded that satisfactory performance is achieved in MLTC-CPFSK systems for all SNR values in various fading environments. (C) 2008 Elsevier Ltd. All rights reserved.
In this letter, we propose three noncoherent block-coded twisted amplitude and phase shift keying (NBC-TAPSK) schemes which are derived from noncoherent block-coded MPSK. We also propose a new noncoherent detector and...
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In this letter, we propose three noncoherent block-coded twisted amplitude and phase shift keying (NBC-TAPSK) schemes which are derived from noncoherent block-coded MPSK. We also propose a new noncoherent detector and a corresponding noncoherent distance for nonconstant-energy signals over the additive white Gaussian noise (AWGN) channel. At high data rates, NBC-8TAPSK has the best bit error performance among all noncoherent schemes.
The design of multilevel turbo codes using M-PSK is optimized to achieve a low bit error rate (BER). Unequal error protection is employed via group set partitioning in multi-stage decoding to minimize the error propag...
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The design of multilevel turbo codes using M-PSK is optimized to achieve a low bit error rate (BER). Unequal error protection is employed via group set partitioning in multi-stage decoding to minimize the error propagation and BER. Simulation results are performed under Gaussian and Rayleigh fading channels to depict the superiority of the new scheme. Copyright (C) 2008 John Wiley & Sons, Ltd.
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