time coding for cdma systems

... Space -Time Coding for CDMA Systems 8.10 Performance of STTC in CDMA Systems 8.10.1 Space -Time Matched Filter Detector 8.10.2 Space -Time MMSE Multiuser Detector 8.10.3 Space -Time ... Diversity for CDMA 8.8.3 Closed-Loop Transmit Diversity for CDMA 8.8.4 Time- Switched Orthogonal Transmit Diversity (TS-OTD) 8.8.5 Space -Time Spreading (STS) 8.8.6 STS for ... Space -Time Modulation Unitary Group Codes Space -Time Coding for Wideband Systems 8.1 Introduction 8.2 Performance of Space-Time...

Ngày tải lên: 26/10/2014, 14:30

... thesis, space -time coding schemes for multiuser and single user systems are discussed Based on the performance analysis, the code design criteria for multiuser composite fading systems are obtained ... space -time CDMA code division multiple access CSI channel state information DLAST diagonally layered space -time code GSM Global System for Mobile Communication HLST horizontally layered space -time ... in the performance curve Compared to the code design for single user systems, the code design for multiuser narrow band systems receives little attention Most researches focus on the decoding and...

Ngày tải lên: 14/09/2015, 12:11

... malicious attackers PERFORMANCE ANALYSIS OF CDMA SYSTEMS WITH SECURE SCRAMBLING Pseudorandom scrambling in CDMA systems provides physical layer built-in user privacy for information transmission ... SECURITY EVALUATION OF IS-95 AND 3GPP UMTS CDMA SYSTEMS 10 (5) + x + x + x + x + x + x + x + 1, In the operational and proposed direct-sequence CDMA (DS -CDMA) systems, as shown in Figure 1, each user’s ... s6 s5 s4 s3 s2 s1 s0 Figure 3: Scrambling sequence for 3GPP and the built-in information privacy provided by the operational and proposed CDMA systems is far from being adequate In this paper,...

Ngày tải lên: 22/06/2014, 19:20

... Performance analysis for GLRT decision rule For the optimum ML decision rule, a closed-form performance analysis does not seem to be feasible However, fortunately such an analysis is possible for ... obtain the results for the ML decision rule For complexity reasons, for the latter case, we only show the results for K ≤ For error-free local sensor decisions, BER is constant for K > N since the ... decisions are performed on a symbol-by-symbol basis making coherent data fusion at the FC practically impossible In this paper, we consider noncoherent distributed spacetime block coding for transmission...

Ngày tải lên: 22/06/2014, 19:20

... low-complexity space -time coding for quasi-static channels,” IEEE Trans Inform Theory, vol 49, no 6, pp 1400–1416, 2003 [27] G K Kaleh, “Channel equalization for block transmission systems, ” IEEE J ... technologies for IMT-2000,” 1997 [35] “TD-SCDMA,” http://www.tdscdma-forum.org [36] Y Liu, M P Fitz, and O Y Takeshita, “Space -time codes performance criteria and design for frequency selective fading channels,” ... estimation for time- reversal space -time block-coded transmission,” IEEE Trans Veh Technol., vol 53, no 4, pp 1273–1278, 2004 [17] N Al-Dhahir, “Decision-feedback sequence estimation for time- reversal...

Ngày tải lên: 23/06/2014, 00:20

... Real -Time Embedded Systems In the simplest form, real -time systems can be defined as those systems that respond to external events in a timely fashion, as shown in Figure 1.5 The response time ... before reaching a given deadline In other words, real -time systems have timing constraints and are deadline-driven Real -time systems can be classified, therefore, as either hard real -time systems ... 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

... transmitted signal for 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 ... scheme for wideband CDMA systems based on space -time spreading IEEE J Sel Areas Commun 19, 48–60 (2001) [8] L-L Yang, L Hanzo, Performance of broadband multicarrier DS -CDMA using spacetime spreading-assisted ... MIMO OFDM -CDMA system block diagram Fig (T-F) Time- frequency mapping Fig Probability density function for SINR for Es /σ =20 dB for our proposed scheme (solid) and 2D OFDM -CDMA (dotted), for both...

Ngày tải lên: 18/06/2014, 22:20

... Performance Evaluation for Zero Forcing Receiver In this section, we will calculate probability of bit error for Zero-Forcing receiver (ZF) [18,19] to examine the performance of our space -time- frequency ... 2D OFDM CDMA (sim.) Proposed OFDM CDMA (theo.) 2D OFDM CDMA (theo.) 18 16 14 % 12 10 0 10 15 20 25 30 35 40 45 50 SINR (dB.) Figure Probability density function for SINR for Es/s = 20 dB for our ... scheme for wideband CDMA systems based on space -time spreading IEEE J Sel Areas Commun 19, 48–60 (2001) doi:10.1109/49.909608 L-L Yang, L Hanzo, Performance of broadband multicarrier DS -CDMA using...

Ngày tải lên: 20/06/2014, 21:20

... channel coding are present in CDMA systems: convolutional coding and turbo coding Convolutional coding is exclusively used in second-generation CDMA systems However, turbo coding has been adopted for ... these third-generation CDMA systems to provide improved services for cellular packet data users This effort has resulted in the 1X-EV system for cdma2 000 and HSDPA for WCDMA This book is intended ... century begins, CDMA systems will once again find widespread use in the form of third-generation cellular systems However, two third-generation systems based on CDMA, cdma2 000 and WCDMA, have emerged...

Ngày tải lên: 18/04/2014, 12:26

... state information (CSI); or, more generally, for the transmission of sensitive data such as control information, where a good reliability is required despite the absence of feedback information ... channel [14] Therefore, it is after the DFT precoding that a transmit diversity precoding module must be inserted, in order to be able to correctly apply at subcarrier level space -time (ST) or spacefrequency ... FER of × 10-2 , for MS0 , both schemes exhibit similar performance For MS1, the MU SC-SFBC with incompatible Conclusions and future work SC-FDMA imposed itself as a good option for the uplink...

Ngày tải lên: 21/06/2014, 00:20

... test the performance of a DS -CDMA system when different choices of the spreading codes are performed, as discussed in section “Evaluation of binary De Bruijn sequences in DS -CDMA systems. ” Binary ... span n and period L, for a given shift τ, the known results are as follows: ⎧ n ⎨ for τ = 0, θc (τ ) = for1 ≤ |τ | ≤ n − 1, (6) ⎩ = for| τ | = n L−1 L−1 ci ci+τ = 2n 2n + , for ≤ τ ≤ L − (8) where ... in DS -CDMA systems evaluates the applicability of De Bruijn sequences in DSCDMA by providing several results obtained through simulations; finally, the article concludes System Model DS-CDMA...

Ngày tải lên: 21/06/2014, 03:20

... practice, transition time is a random variable for a sampling data block The transition time K is set randomly between and M with a uniform distribution As indicated in Figure 6, the performance of the ... 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...

Ngày tải lên: 21/06/2014, 08:20

... done before despreading Therefore, the notch filter will destruct the orthogonality and is not feasible for MCCDMA systems The frequency-domain channel-estimation methods in the MC -CDMA systems ... CDMA systems [23–27] The channel parameters are then estimated after despreading But in the MC -CDMA systems, the objective of channel estimation is to make the gain of each subchannel equal for ... other is that the parameter estimation in (19) is in block form, which is not suitable for realtime design in the MC -CDMA communication systems A (21) It, of course, cannot be implemented since...

Ngày tải lên: 21/06/2014, 08:20

... z−1 DS -CDMA MODEL ⎡ Order xi (n) si (n) r i (z) 1×M ↓M (b) Figure 1: (a) DS -CDMA transmitter number i (b) DS -CDMA receiver part designed for decoding user number i 2.2 Transmission model for ... 35 40 MMSE DS -CDMA system BER DS -CDMA system Figure 3: BER versus Eb / N0 performances of the MMSE DSCDMA system (· · · ◦ · · · ) and the proposed minimum BER DSCDMA system (− × −) for different ... 10−15 MMSE DS -CDMA system BER DS -CDMA system Figure 4: BER versus Eb / N0 performances of the MMSE DSCDMA system (· · · ◦ · · · ) and the proposed minimum BER DSCDMA system (− × −) for different...

Ngày tải lên: 21/06/2014, 22:20

... we present the turbo space -time coded MIMOCDMA system model Section presents MMSE space -time receivers for coded MIMO -CDMA systems In Section 4, we present turbo space -time receivers that employ ... joint DS -CDMA space -time MUD system with error control coding over a multipath fading channel The authors of [20] use convolutional coding for error control coding and a space -time MMSE detector ... streams for all K users are combined during the wireless transmission process A synchronous Rayleigh flat fading uplink MIMO -CDMA channel is considered MMSE SPACE -TIME RECEIVERS FOR CODED MIMO -CDMA SYSTEMS...

Ngày tải lên: 21/06/2014, 23:20

... MULTIPATH FADING CDMA CHANNEL For the case of asynchronous CDMA multipath fading channel, the structure presented in Figures and are the same, only the spreading code matrix for the gth group ... BSOR-GSIC detector versus the relaxation factor for the case of asynchronous CDMA multipath Rayleigh fading channel factor of about 1.2 for G = and 1.4 for G = 10 It is easy to note that the proposed ... receivers for cellular CDMA, ” IEEE Transactions on Vehicular Technology, vol 49, no 4, pp 1065–1085, 2000 [3] K Jamal and E Dahlman, “Multi-stage serial interference cancellation for DS -CDMA, ” in...

Ngày tải lên: 22/06/2014, 00:20

... MULTIPATH FADING CDMA CHANNEL For the case of asynchronous CDMA multipath fading channel, the structure presented in Figures and are the same, only the spreading code matrix for the gth group ... BSOR-GSIC detector versus the relaxation factor for the case of asynchronous CDMA multipath Rayleigh fading channel factor of about 1.2 for G = and 1.4 for G = 10 It is easy to note that the proposed ... receivers for cellular CDMA, ” IEEE Transactions on Vehicular Technology, vol 49, no 4, pp 1065–1085, 2000 [3] K Jamal and E Dahlman, “Multi-stage serial interference cancellation for DS -CDMA, ” in...

Ngày tải lên: 22/06/2014, 06:20

... macroscopic subsystems known as compartments The range of applications of nonnegative systems and compartmental systems includes pharmacological systems, queuing systems, stochastic systems whose ... state variables represent probabilities , ecological systems, economic systems, demographic systems, telecommunications systems, and transportation systems, to cite but a few examples Due to the severe ... Lyapunov-like theorems for partial boundedness and partial ultimate boundedness for nonlinear dynamical systems necessary for obtaining less conservative ultimate bounds for neuroadaptive controllers...

Ngày tải lên: 22/06/2014, 11:20

... of classes Data rate for packet i Transmitted power for packet i Bandwidth Link gain for packet i Array response vector for packet i Arrival rate for class j Departure rate for class j Blocking ... constraint for class j Connection delay constraint for class j Maximum number of retransmissions for class j Target PER for class j Achieved overall PER for class j Achieved instantaneous PER for class ... j Target SIR for class j Buffer size for class j Beamformer weight for packet i One-sided power spectral density of additive white Gaussian noise (AWGN) SIGNAL MODEL AND PROBLEM FORMULATION Signal...

Ngày tải lên: 22/06/2014, 19:20