time turbo trellis codes

... space -time code space -time block code space -time trellis code space -time spreading singular value decomposition trellis coded modulation time division multiple access threaded layered space -time ... Design of Space -Time Trellis Codes on Fast Fading Channels Performance Evaluation on Fast Fading Channels Space -Time Turbo Trellis Codes 5.1 Introduction ... STTC 5.3 Space -Time Turbo Trellis Codes 5.4 Decoding Algorithm 5.4.1 Decoder Convergence 5.5 ST Turbo TC Performance ...

Ngày tải lên: 26/10/2014, 14:30

... Space -time Trellis Code and Space -time Block Code In this section, we will show the principles of the STTC and STBC Space -time Trellis Codes STTC is a two-dimensional extension of the traditional trellis ... chapters 2.2 Space -time Codes In this section, we will give an overview of STCs and briefly explain its principle 2.2 Space -time Codes 25 st1 Spacetime Encoder yt1 stnT ytnR Spacetime Decoder noitamrofnI ... cancellation SNR signal-to-noise ratio SQRD sorted QRD ST space -time STC space -time code STTC space -time trellis code STBC space -time block code TCM trellis coded modulation UMTS Universal Mobile Telecommunication...

Ngày tải lên: 14/09/2015, 12:11

... implement and can readily be applied to 3G systems and beyond Since the channelization codes are chosen to be Walsh codes, which are easy to generate, the physical layer built-in security of CDMA systems ... and S(t) = [s1 (t), s2 (t), , s42 (t)] denote the state of the LFSR at time instance t The long-code sequence c(t) at time t can thus be represented as c j = c j (0), c j (1), , c j (N − ... 3GPP UMTS standard, Gold codes generated from two generator polynomials of degree 18 are used as scrambling code, as shown in Figure Denote the states for the two LFSRs at time instance t as r(t)...

Ngày tải lên: 22/06/2014, 19:20

... application of coherent distributed space -time coding was proposed in [11] In particular, in [11] each sensor is randomly assigned a column of Alamouti’s space -time block code (STBC) [12] and it is ... 2.3 Channel model We assume that the sensors transmit time synchronously and that the sensor-FC channels are frequency-nonselective and time- invariant for at least T symbol intervals.2 Therefore, ... Lampe, “Distributed space -time block coding,” IEEE Transactions on Communications, vol 54, no 7, pp 1195–1206, 2006 [15] B S Mergen and A Scaglione, “Randomized space -time coding for distributed...

Ngày tải lên: 22/06/2014, 19:20

... decoding For example, trellis coding and bit-interleaved coded modulation (BICM) with turbo equalization have been proposed in [9, 13] Time- reversal orthogonal space -time block codes (TR-STBC) [8] ... the Viterbi decoder acting on the trellis of the TCM code Since the joint equalization and decoding scheme works on the trellis of the original TCM code, without trellis state expansion due to the ... [0], , gi [Ng − 1], 0, ,  (2) Ns (N −n−1) nNs 2.2 Time- reversal STBC TR-STBC [8] is a clever extension of orthogonal spacetime block codes based on generalized orthogonal designs (GODs) [19,...

Ngày tải lên: 23/06/2014, 00:20

... results within a given time constraint Timing constraints include finish time, or both start time and finish time A good way to understand the relationship between real -time systems and embedded ... deadline-driven Real -time systems can be classified, therefore, as either hard real -time systems or soft real -time systems What differentiates hard real -time systems and soft real -time systems are ... real -time systems Figure 1.7: Structure of real -time systems 1.2.1 Real -Time Systems This document is created with the unregistered version of CHM2PDF Pilot The environment of the real -time system...

Ngày tải lên: 08/03/2016, 11:37

... user k from antenna i at time n 3) Time- Frequency mapping : The output of the space -time spreading is then mapped in time and frequency before IFFT Fig describes the Time- Frequency mapping method ... more complexity than our proposed system Their spreading technique uses space -time block codes or space -time trellis codes and then uses subcarrier selectors to map signals to different OFDM frequency ... spread in time and frequency, occupying different time and frequency slots, where each bit is spread to ensure frequency independence as shown in Fig Also, other systems that use space -time- frequency...

Ngày tải lên: 18/06/2014, 22:20

... user k from antenna i at time n 3) Time- Frequency mapping The output of the space -time spreading is then mapped in time and frequency before IFFT Figure describes the Time- Frequency mapping method ... for SINR for Es/s = 20 dB for our proposed scheme with different number of users codes or space -time trellis codes and then uses subcarrier selectors to map signals to different OFDM frequency ... spread in time and frequency, occupying different time and frequency slots, where each bit is spread to ensure frequency independence as shown in Figure Also, other systems that use space -time- frequency...

Ngày tải lên: 20/06/2014, 21:20

... 2-1 : Turbo Code Also note that the input bits are sent unencoded in the turbo code These bits are sometimes called systemtic bits and are important for the turbo decoding process 39 The turbo ... detailed description of the trellis representation and Viterbi decoding algorithm may be found in [7] Figure 2-16: Trellis for IS-95 Convolutional Code 8.2 Turbo Encoding Turbo encoding was incorporated ... 2-15: Is-95 Convolutional Code 37 The trellis represents the state transitions from all the nodes of a given stage of the trellis to the next stage of the trellis A stage is associated with each...

Ngày tải lên: 18/04/2014, 12:26

... correctly apply at subcarrier level space -time (ST) or spacefrequency (SF) block codes (BC) that were originally designed for narrowband channels In Figure 1, at time t, data block vector (t) (t) (t) ... is easily decodable If trying to apply an Alamouti-based STBC (i.e., precoding in the time domain between time- consecutive frequency samples s(t00 ) and s(t01 =t0 +1)carried by the same k k k0 ... to the same SC-FDMA symbol The main difference with respect to classical SFBC is that SC-SFBC precodes between non-adjacent frequency samples s(t00 ) and k (t ) sk 0= p−1−k mod M, where M is the...

Ngày tải lên: 21/06/2014, 00:20

... codes [6] are adopted in Wideband CDMA as channelization codes, thanks to the orthogonality ensured by codes belonging to the same set, i.e., at a parity of their Spreading Factor (SF) OVSF codes ... sequences are adopted as channelization codes in Wideband CDMA (WCDMA), together with Gold codes used as information scrambling sequences The main feature of OVSF codes that are derived from WalshHadamard ... because it is a measure of the agreement between different codes, i.e., of the channel separation capability The same family of spreading codes may provide very different performances when evaluating...

Ngày tải lên: 21/06/2014, 03:20

... When the computational complexity of an algorithm is polynomial time instead of exponential time, that algorithm is feasible for real -time EURASIP Journal on Advances in Signal Processing 600 1.8 ... proposed scheme is O(NM), which is polynomial time rather than exponential time An algorithm with a complexity of O(MN) can be treated as feasible for real -time application Simulations Results In this ... and the computing time of the proposed algorithm is much lower than that of the ML-based greedy search scheme Notably, the computing time can be reduced by optimizing the program codes and designing...

Ngày tải lên: 21/06/2014, 08:20

... estimation [12], the spaces between pilots in the time domain are chosen according to coherence time Tc ≈ 9/16π fd [32] if the coherent time is defined as the time over which the correlation function is ... MC-CDMA systems can be simultaneously estimated in real time Since the proposed method works EURASIP Journal on Advances in Signal Processing in the time domain, it can significantly reduce the number ... driving noise in the time domain with a simple scheme The MMSE detector will be enhanced by using the estimated parameters The proposed channel-estimation method can work in the time domain because...

Ngày tải lên: 21/06/2014, 08:20

... A(η) Let ν be a nonnegative integer The symbol n is used as a time index in this article and n is an integer Let y(n) be a vector time- series of size M × The column expansion of y(n) of order ... part of the ith noise-free eye diagram at time instant n is defined as the real part of the noise-free signal at the output of the receiver filter ri (z) at time n when the desired signal is di (n) ... of the output of the ith MISO receiver filter ri (z) at time n when the vector given by s(i) (n) was transmitted with no channel noise At time n, the ith receiver filter ri− is trying to estimate...

Ngày tải lên: 21/06/2014, 22:20

... punctured turbo codes The numerical results are discussed in Section 5, and Section concludes this paper TURBO SPACE -TIME CODED MIMO-CDMA SYSTEM A MIMO-CDMA system that employs turbo codes and space time ... poor parity data decoding performance characteristic of turbo codes Rate compatible punctured turbo codes are investigated in a turbo space -time coded MIMO-CDMA system as a possible way of achieving ... (t) b1 Turbo encoder d1 Π ST-demux d1 n1 nT r1 n2 n d1 T r2 cK (t) dK bK Turbo encoder dK Π ST-demux dK Turbo space -time multi-user receiver d1 nT rnR nnR n dKT Figure 1: Turbo...

Ngày tải lên: 21/06/2014, 23:20

... chip-level linear BSOR-GSIC detector where S is an N × K matrix of linearly independent spreading codes, A is a K × K matrix of the received amplitudes, b is a K-length vector of transmitted binary ... group consists of Ug users such that K = U1 + U2 + · · · + UG and thus the matrix of spreading codes can be partitioned as S = (S1 , S2 , , Sg , , SG ) where Sg = (sg,1 , sg,2 , , √ ... sg,Ug ) ∈ {−1/ N, 1/ N } g We define R = ST S as the cross-correlation matrix of the spreading codes, Ri, j = ST S j as the (ith, jth) submatrix of R, and Ag as the gth dii agonal submatrix of...

Ngày tải lên: 22/06/2014, 00:20

... chip-level linear BSOR-GSIC detector where S is an N × K matrix of linearly independent spreading codes, A is a K × K matrix of the received amplitudes, b is a K-length vector of transmitted binary ... group consists of Ug users such that K = U1 + U2 + · · · + UG and thus the matrix of spreading codes can be partitioned as S = (S1 , S2 , , Sg , , SG ) where Sg = (sg,1 , sg,2 , , √ ... sg,Ug ) ∈ {−1/ N, 1/ N } g We define R = ST S as the cross-correlation matrix of the spreading codes, Ri, j = ST S j as the (ith, jth) submatrix of R, and Ag as the gth dii agonal submatrix of...

Ngày tải lên: 22/06/2014, 06:20

... by equivalently representing the time- varying discrete -time system 2.10 as an autonomous discrete -time nonlinear system by appending another state to represent time Specifically, defining y k − ... 25 30 35 Discrete time k 40 45 50 40 45 50 x1 k x2 k a Control signal 0.5 −0.5 −1 10 15 20 25 30 35 Discrete time k uk b Figure 2: State trajectories and control signal versus time guarantees that ... , T ∈ R12 , Figure shows the state trajectories versus time and the control signal versus time Neuroadaptive control for discrete -time nonlinear nonnegative uncertain systems with nonnegative...

Ngày tải lên: 22/06/2014, 11:20

... “High-rate codes that are linear in space and time, ” IEEE Transactions on Information Theory, vol 48, no 7, pp 1804–1824, 2002 V Tarokh, N Seshadri, and A R Calderbank, “Space -time codes for high ... Therefore, the service time of a packet can comprise at most L + transmission rounds Each transmission round includes the actual transmission time of the packet and the waiting time of an ACK signal ... consider the decision epoch as the time instances that a packet arrives or departs As we discussed in the previous section, based on these decision epoches, the time interval until the next state...

Ngày tải lên: 22/06/2014, 19:20