• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.187-195
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• 1996

The purpose of this paper is to provide an algorithm in which the procedure of constructing a superstate transition matrix for trellis codes is reduced and, as a result, make it easier to evaluate the performance of a TCM scheme when the generalized transfer function method is used. In this paper, an algorithm for constructing a superstate transition matrix and an algorithm for reducing the matrix easily are addressed and applied to an MTCM scheme as an example. It is shown that the algorithm is very useflul for trellis codes with a large number of states and/or parallel transitions.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.4
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• pp.39-46
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• 1994

In this paper, the idea of using a multiple symbol obervation interval to improve error probability performance is applied to differential detection of MTCM(multiple trellis code modulation) with ${\Pi}$/4 shift QPSK, 8DPSK and 16DPSK. We propose two types of sliding multiple symbol differential detection algorithm, type 1 and type 2. The two types of sliding detection scheme are examined and compared with conventional(symbol-by-symbol) detection and bolck detection with these modulation formats in an additive white Gaussian noise(AWGN) using the Monte Carlo simulation. We show that the amount of improvement over conventional and block detection depends on the number of phases and the number of additional symbol intervals added to the observation. Computer simulagtion results are presented for 2,4,8 states in AWGN channel.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.9
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• pp.1-8
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• 1999

In this paper, we propose and analyze a concatenated coding scheme for DS/CDMA systems in asynchronous channels. In the concatenated coding, bandwidth efficient $2^{2L-2}$-state ${\frac{L}{L+1}}$-rate 2-MTCM with biorthogonal signal constellation is used for the inner code, and $(2^{L-1},\;{\lceil}\frac{2^{L-1}}{L/2}{\rceil})$ RS code is use for the outer code. It is shown that we can get considerable performance gain over the uncoded system without sacrificing the data transmission rate. The proposed system can be used as a coding scheme for reliable and high speed integrated information services of mobile communication systems.