C. Fragouli and R. D. Wesel, "Turbo encoder design for symbol-interleaved parallel concatenated trellis-coded modulation," in IEEE Transactions on Communications,  Home/Search   Document Details and Download   Summary   Related Articles   Check

....to be carried out however, the (L) column must have only one non zero entry in the L row. D. Simulation Results In figure 14 we compare the results we had from the code optimized with the Gaussian approximation with maximum left degree 20 coupled with iterative demodulation to that of [12] the best result from Turbo TCM designed code for 8 PSK modulation format. The construction of the LDPC code was done randomly, and the length of 38 the code was 30000 bits. We call this LDPC code as G1. The labeling used was Gray and Bit interleaved coded modulation scheme was used. From the ....

Christine Fragouli and Richard D. Wesel, "Turbo Encoder Design for symbol interleaved parallel concatenated Trellis Coded Modulation," to appear in IEEE transactions on comm.

....in the first trellis code and the other half in the second trellis code [12] This is done to limit the number of points in the signal constellation to 2 (k 2) 1 . Also, the information bits transmitted by the two trellis encoders are interleaved by di#erent bit interleavers (see Figure 4) In [13], a variation of this scheme is presented where a symbol interleaver is used instead of bit interleavers, resulting in improved BER performance in the waterfall region. D. Multilevel Coding Wachsmann and Huber use binary turbo codes as constituent codes in a multi level coding arrangement [14] ....

C. Fragouli and R. D. Wesel, "Turbo encoder design for symbol interleaved parallel concatenated trellis coded modulation," in IEEE Transactions on Communications, Mar. 2001, vol. COM-49, pp. 425--435.

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C. Fragouli and R. D. Wesel, "Turbo encoder design for symbol-interleaved parallel concatenated trellis-coded modulation," in IEEE Transactions on Communications,

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C. Fragouli and R. Wesel, "Turbo encoder design for symbol-interleaved parallel concatenated trellis coded modulation," IEEE Trans. on Comm., vol. 49, no. 3, pp. 425--35, March 2001.

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C. Fragouli and R. D. Wesel, "Turbo-encoder design for symbol-interleaved parallel concatenated trellis-coded modulation," IEEE Trans. Commun., vol. 49, pp. 425--434, Mar. 2001.

....If only Constraint 1 is imposed, a necessary and sufficient condition for at least one interleaver of length N to exist is: N S1S2 To prove that this is a sufficient condition we show how to construct two different interleavers of length 152. The proof for the necessary part is provided in [8]. Consider a block interleaver of dimensions 2 x 1. Write the numbers 1. N by columns. Each column has length 2 so the elements in each row differ by exactly 2: I 2 1 2 2 2 : SS 1) 2 1 ] iii 11 1 s2 2 . S1 S2 Reading though the rows starting from the upper left corner we get an ....

C. Fragouli and R. Wesel. Turbo Encoder Design For Symbol Interleaved Parallel Concatenated Trel- lis Coded Modulation. IEEE Transactions on Com- munications, submitted April 1999.

....a better structure for joint channel estimation and turbo decoding based on the Forward Backward algorithm running on separate trellises for the channel phase and the code. Fig. 6 shows the transmitter block diagram, where the constituent encoders are the best 8 state, rate 2 2 code fragments [21] [22], each producing one systematic and one parity bit per 2 bit input, and their outputs are mapped onto a Gray labeled 4 PSK constellation. No 6 C. KOMNINAKIS AND R. D. WESEL: JOINT ITERATIVE CHANNEL ESTIMATION AND DECODING IN FLAT CORRELATED RAYLEIGH FADING tice the difference between the turbo ....

C. Fragouli and R. Wesel. Turbo encoder design for symbol-interleaved parallel concatenated trellis coded modulation. to appear in IEEE Transactions on Communications, 2000.

....constellation) The small distance of points near the center of the constellation may lead to a small overall free distance and thus a high error floor for turbo codes. We avoid this situation by a two step design procedure, that first creates an interleaver according to the criteria in [1], and then identifies the constituent encoders that maximize the turbo code free distance. Simulation results for bits sec Hz show that this use of shaping can offer an improvement of approximately dB for turbo codes. I. INTRODUCTION This paper presents a method for parallel concatenated ....

....way that the output signal approximately follows a Gaussian distribution. This approach can offer shaping gain of up to 1 dB [12] for high order constellations. Our proposed approach combines the nonuniform constellation [10] 11] 12] with the symbolinterleaved turbo encoder introduced in [13] [1]. The paper is organized as follows. Section II reviews shaping with non uniform constellations, discusses the peak to average power ratio and the constellation labeling. Section III optimizes the turbo encoder. Section IV presents simulation results, and finally Section V concludes the paper. ....

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C. Fragouli and R. D. Wesel. Turbo encoder design for symbolinterleaved parallel concatenated trellis-coded modulation. In IEEE Transactions on Communications, volume 49, March 2001.

....turbo trellis code of Figure 2 are depicted in Figure 1. They are characterized by the octal polynomial (h 0 #h 1 #h 2 #h 3 #h 4 ) 13# 1# 17# 13# 17) the meaning of which is described in Figure 1. These constituent encoders are optimal for an AWGN channel by the criteria proposed in [10], 11] For the upper encoder the input bit u 0 is punctured. For the lower encoder the input bit u 1 is punctured. The turbo interleaver (TIL) of Figure 2 is a 4098 symbol randomly generated interleaver with 2 input bits per symbol. The input bits are flipped in each interleaved symbol, as shown ....

C. Fragouli and R. D. Wesel. Turbo Encoder Design for Symbol Interleaved Parallel Concatenated Trellis Coded Modulation. IEEE Trans. on Comm., 2001.

....of interest is an exhaustive set of encoders that are strictly distinct. Two encoders are called strictly equivalent [9] if they map the same input sequence to the same output sequence. If two encoders are not strictly equivalent we say they are strictly distinct. The rational form theorem in [10] provides a method for identifying an exhaustive set of strictly distinct encoders. A group theoretic approach in [11] provides a different way of identifying such a set. III. ALGORITHM TO DETERMINE ZERO OUTPUT LOOPS UNDER SYMBOL PUNCTURING The straightforward method described in [2] to determine ....

C. Fragouli and R. D. Wesel. Turbo encoder design for symbolinterleaved parallel concatenated trellis-coded modulation. In IEEE Transactions on Communications, March 2001.

....a better structure for joint channel estimation and turbo decoding based on the Forward Backward algorithm running on separate trellises for the channel phase and the code. Fig. 6 shows the transmitter block diagram, where the constituent encoders are the best 8 state, rate 2 2 code fragments [21] [22], each producing one systematic and one parity bit per 2 bit input, and their outputs are mapped onto a Gray labeled 4 PSK constellation. Notice the difference between the turbo interleaver (TIL) and the channel interleaver (CIL) which can be a regular block interleaver. Pilots are injected into ....

C. Fragouli and R. Wesel. Turbo encoder design for symbol-interleaved parallel concatenated trellis coded modulation. to appear in IEEE Transactions on Communications, 2000.

No context found.

C. Fragouli and R. D. Wesel, "Turbo-encoder design for symbolinterleaved parallel concatenated trellis-coded modulation," IEEE Transactions on Communications, vol. 49, no. 3, pp. 425--435, March 2001.

No context found.

C. Fragouli and R. D. Wesel, "Turbo-encoder design for symbolinterleaved parallel concatenated trellis-coded modulation," IEEE Transactions on Communications, vol. 49, no. 3, pp. 425--435, March 2001.

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