F.-W. Sun and H. C. A. van Tilborg, "Approaching capacity by equiprobable signaling on the Gaussian channel," IEEE Trans. Inform. Theory, vol. 39, pp. 1714--1716, Sept. 1993.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....Since inner points are closer to each other than points at the perimeter of the constellation, a nonuniform density is present. Hence, by selecting and optimizing the ring ratio, this density can be adjusted. Note that this procedure is comparable to the way of approaching AWGN channel capacity in [29] and has similarities with warping [30] where regularly spaced signal constellations are nonlinearly distorted. Consequently, we will use the term capacity for the mutual information given the uniformly distributed constellation and normalized with respect to the number 1 of differential ....

F.-W. Sun and H. C. A. van Tilborg, "Approaching capacity by equiprobable signaling on the Gaussian channel," IEEE Trans. Inform. Theory, vol. 39, pp. 1714--1716, Sept. 1993.

....this case where the quantization error is uniformly distributed over the interval and statistically independent of [29] Thus, the achievable rate is slightly lower than the case where is Gaussian. The entropy power inequality can be used to show that the decrease in achievable rate is bounded by [36] DNR DNR (54) This gap approaches the upper limit of 0.2546 b dimension as the DNR gets large. For any finite DNR, the gap is smaller. By subtracting the upper bound on the gap (54) from the capacity (38) one obtains a lower bound on the achievable rate of this type of dither modulation DNR ....

F.-W. Sun and H. C. A. van Tilborg, "Approaching capacity by equiprobable signaling on the Gaussian channel," IEEE Trans. Inform. Theory, vol. 39, pp. 1714--1716, Sept. 1993.

....for Noncoherent Reception with Application to OFDM 7 the perimeter of the constellation, a non uniform density is present. Hence, by selecting and optimizing the ring ratio, this density can be adjusted. Note that this procedure is comparable to the way of approaching AWGN channel capacity in [29], and has similarities with warping [30] where regularly spaced signal constellations are non linearly distorted. Consequently, we will use the term capacity for the mutual information given the uniformly distributed constellation and normalized with respect to the number N 1 of di erential ....

F.-W. Sun and H.C.A. van Tilborg. Approaching Capacity by Equiprobable Signaling on the Gaussian Channel. IEEE Trans. on Information Theory, 39:1714-1716, September 1993.

....D. Sommer and G. P. Fettweis are with the Dresden University of Technology. C. Fragouli and R. D. Wesel were supported by NSF CAREER award #9733089, and the Xetron Corporation. 9] uses an asymmetric coded modulation scheme to optimize trellis coding. In this paper we use the method in [10] [11], to obtain shaping gain for turbo codes. Each constellation point is transmitted with the same probability. However, the distance between the constellation points varies in such a way that the output signal approximately follows a Gaussian distribution. This approach can offer shaping gain of up ....

....However, the distance between the constellation points varies in such a 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 ....

F. Sun and H. Tilborg. Approaching capacity by equiprobable signaling on the gaussian channel. IEEE Transactions on Info. Theory, pages 1714--1716, September 1993.

....error e is uniformly distributed over the interval [ # 2, # 2] and statistically independent of x [29] Thus, the achievable rate I(e; e n) is slightly lower than the case where e is Gaussian. The entropy power inequality can be used to show that the decrease in achievable rate is bounded by [36] C Gauss,known R dith # 1 2 log 2 1 DNR 1 (6 #e)DNR . 54) This gap approaches the upper limit of 1 2 log 2 #e 6 # 0.2546 bits dimension as the DNR gets large. For any finite DNR, the gap is smaller. By subtracting the upper bound on the gap (54) from the capacity (38) one ....

F.-W. Sun and H. C. A. van Tilborg, "Approaching capacity by equiprobable signaling on the Gaussian channel," IEEE Transactions on Information Theory, vol. 39, pp. 1714--1716, Sept. 1993. 54

....redundancy. Only for asymptotically high rates does the whole shaping gain translate directly to a gain in capacity, approaching the ultimate shaping gain of e 6 . This is because C u 1 2 Delta log 2 Gamma 6 e (1 2E s =N 0 ) Delta for high signal to noise ratios (cf. 74] [75]) In contrast, for C 0 the capacity gain completely vanishes. Note that an additional loss appears for discrete constellations compared to the corresponding continuous ones. Hence, for discrete constellations (53) is actually a lower bound. In order to come close to the optimum, an optimization ....

F.-W. Sun and H.C.A. van Tilborg, "Approaching Capacity by Equiprobable Signaling on the Gaussian Channel," IEEE Trans. Inf. Theory, vol. vol.39, pp. 1714--1716, Sept. 1993.

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