maximum likelihood decoding of convolutional codes

Ngày tải lên: 24/04/2014, 13:16

... unit matrix. 3. Maximum A Posteriori Decoding of Channels Codes The BCJR algorithm [28] provides the common framework to the decoding of turbo and LDPC codes as it is applied to the decoding of the two ... Channel Codes 2.1. Turbo Codes. Focusing on the class of parallel concate- nated convolutional code (PCCC) codes, Figure 1 shows the encoder of the 3GPP-LTE turbo code. This is composed of two ... the definition of turbo and LDPC codes, and Section 3 reviews the fundamentals of the MAP decod- ing algorithm, going through the BCJR decoding of con- volutional codes, the turbo decoding principle...

Ngày tải lên: 21/06/2014, 05:20

... noncoherent decoding of turbo-like codes for the phase-noisy channels. These schemes make use of pilot symbols for either estimation or decoding. In [5], the authors showed the rotational robustness of ... DVB-S2). The severity of the phase noise depends on the quality of the local oscillators and the symbol rate. Hence the performance of codes on the channels with phase disturbances are of practical significance. Over ... iterative decoding for the convergence of these codes. We also show the additional computational complexity required due to the phase estimation process. In Section 6, we discuss the BER performance of...

Ngày tải lên: 21/06/2014, 23:20

... subgraph acts as a relay node, at least one of its outgoing links and one of its incoming links will be included in the subgraph. Otherwise, none of its links will be included in the subgraph. ... logarithmic transformation. However, the maximum multicast throughput in this case would only reach the value of 1.54. This is due to the fact that as a result of the relatively high interference ... link. Recently, the problem of joint optimization of data flow routing and resource allocation in wireless networks when network coding is used in the network layer has also become of interest. Minimum...

Ngày tải lên: 21/06/2014, 23:20

... un- derlying signals. Now we apply f y (y) in a maximum likelihood frame- work to estimate the parameters of the underlying signals. The main objective of the maximum likelihood estimator is to find the kth ... spectrum of the mixed signal is almost ex- actly the elementwise maximum of the log spectrum of the two underlying signals. Table 2: Symbols with definitions. Symbol Description I number of sources ... transform and ϕ y is the phase of the Fourier transform of the windowed mixed signal, that is, ϕ y = ∠y f . In this way, we obtain an estimate of x t i in a maximum likelihood sense. It should be...

Ngày tải lên: 22/06/2014, 22:20

Ngày tải lên: 09/08/2014, 18:22

Ngày tải lên: 09/08/2014, 18:22

Ngày tải lên: 09/08/2014, 18:22

Ngày tải lên: 09/08/2014, 18:22

Ngày tải lên: 09/08/2014, 18:22

Ngày tải lên: 13/08/2014, 16:20

Ngày tải lên: 14/08/2014, 19:22

Ngày tải lên: 14/08/2014, 19:22

Ngày tải lên: 14/08/2014, 20:20

... Fundamentals of Statistical Signal Processing, Prentice-Hall, Englewood Cliffs, NJ, USA, 1993. [12] T. T. Pham and R. J. P. DeFigueiredo, Maximum likelihood estimation of a class of non-Gaussian ... function denotes the gradient vector of the logarithmic likelihood function, whereas H( ·) is the Hessian matrix, composed of the second deviates of the logarithmic likelihood function: g ( Θ ) =  ∂ ... Sieskul and S. Jitapunkul, “An asymptotic maximum likelihood for estimating the nominal angle of a spatially distributed source,” International Journal of Electronics and Communications, vol. 60,...

Ngày tải lên: 21/06/2014, 16:20

... to benefit from soft decisions, several MAP-based algorithms combined with recursive, RLS-based, channel estimation were proposed [19–22]. The combination of MAP decoding and maximum likelihood channel ... subblock approach. The efficiency of a given set of basis functions may be evaluated by calculating the mean square er ror of the fading process representation using this set of functions: E   h − Bg   2 = ... that iterates between detection and decoding stages to improve the performance further. We treat the case of uncorrelated channels paths which is the worst case in terms of number of required BE functions....

Ngày tải lên: 21/06/2014, 16:20

... R S T (k)  . (A.12) B. PROOF OF THE 180 ◦ PERIODICITY OF THE SINGLE SOURCE NONUNIFORM CRB Consider the signal model of Section 2 in the single source case, the pth element of  d(k)ande(k)canbewrittenas   d(k)  p = ... q T  T as the vector of all the un- known parameters in the model, where q = [q 1 , , q P ] T is the vector of the diagonal elements of Q, then the likelihood function of Ψ can be expressed ... 2007 Recommended by Sinan Gezici We investigate the maximum likelihood (ML) direction -of- arrival (DOA) estimation of multiple wideband sources in the presence of unknown nonuniform sensor noise. New closed-form...

Ngày tải lên: 22/06/2014, 06:20

... addresses the problem of optimal and reduced complexity soft-input decoding of QA codes with a termina- tion constraint. An optimal state model for soft -decoding of QA codes, exploiting a termination ... Robust decoding of QA codes with side information 6.3.1. Description of the decoding scheme To improve the robustness of QA codes, many techniques have been proposed as the introduction of a forbidden symbol ... redundancy to QA codes under the form of length constraints all along the decoding pro- cess. This approach improves the decoding of QA codes and outperforms the approach based on QA codes using a...

Ngày tải lên: 22/06/2014, 19:20

... R S T (k)  . (A.12) B. PROOF OF THE 180 ◦ PERIODICITY OF THE SINGLE SOURCE NONUNIFORM CRB Consider the signal model of Section 2 in the single source case, the pth element of  d(k)ande(k)canbewrittenas   d(k)  p = ... q T  T as the vector of all the un- known parameters in the model, where q = [q 1 , , q P ] T is the vector of the diagonal elements of Q, then the likelihood function of Ψ can be expressed ... 2007 Recommended by Sinan Gezici We investigate the maximum likelihood (ML) direction -of- arrival (DOA) estimation of multiple wideband sources in the presence of unknown nonuniform sensor noise. New closed-form...

Ngày tải lên: 22/06/2014, 19:20

... of an RNN decoder [10] first requires the specifi- cation of a number of system characteristics. Of most impor- tance was the choice of convolutional code, as this affects the physical bitrate of ... consisting of a minimal number of arithmetic operations. This particular code provides a cod- ing gain of approximately 3 dB at the BPSK theoretical prob- ability of error of 10 −4 . Hard-decision decoding ... these networks were applied for block codes decoding [2, 3] and then for convolutional [4–7] and turbo codes decoding [8]. In [5–7], it was shown that the decoding problem could be formulated...

Ngày tải lên: 22/06/2014, 23:20