theory and application of spread spectrum systems

... closest transition band and passband of the adjacent sub- channel, but not with the more distant ones. Knowing the elements of this model, the number of af- fected and eliminated subbands can be estimated ... can be estimated from the bandwidth and power of the jammer and from the spectral characteristics of the prototype filter in the filter bank, since its stopband edge and attenuation determine how ... Filter-Bank-Based Narrowband Interference Detection and Suppression in Spread Spectrum Systems Tobias Hidalgo Stitz Institute of Communications Engineering, Tampere University of Technology, P.O.

Ngày tải lên: 23/06/2014, 01:20

... aversion into VaR and ES on the basis of the expected utility theory However, Dowd et al (2008) examined SRM based on this theory and found that the application of exponential utility theory in SRM ... expected utility theory, in the derivation of risk aversion function Starting with Gzyl and Mayoral (2006) and Sriboonchitta et al (2010) and subsequently Sereda et al (2010) and Guegan and Hassani ... estimated SRM and real loss A similar process is implemented with VaR and ES at confidence levels of 95% and 99%, and a comparison of results is used to demonstrate the advantage of SRM 4.3 Data

Ngày tải lên: 03/02/2020, 23:27

... of men in their endeavor to satisfy their demands so as to enable satisfaction of as much of the whole scheme of demands with the least friction and waste has not merely been what lawmakers and ... theory founded on individual interest To escape from a state of nature men devise systems of law which enable them to fulfill "as much of the whole scheme of demands with the least friction and ... of men in their endeavor to satisfy their demands so as to enable satisfaction of as much of the whole scheme of demands with the least friction and waste has not merely been what lawmakers and

Ngày tải lên: 23/10/2022, 15:14

... Review and application of group theory to molecular systems biology Edward A Rietman 1,2,6 , Robert L Karp 3 and Jack A Tuszynski 4,5* * Correspondence: jackt@ualberta. ca 4 Department of Experimental ... explores ideas expanding group theory into contemporary mole- cular systems biology. 2. Introduction to Group Theory Group theory is a branch of abstract algebra developed to study and manipulate ... netwo rk theory and network statistics are Newman et al. [32] and Albert and Barabasi [33]. Godsil and Royle [34] and Chung [35] are good references that go bey ond the statistical analysis of netwo

Ngày tải lên: 13/08/2014, 16:20

... overview of the spread spectrum technique, especially DS-CDMA, is given and examples of potential applications for OFDM and DS-CDMA are analyzed This introduction is essential for a better understanding ... attenuations, and phases The superposition of these waves results in amplitude and phase variations of the composite received signal Multi-Carrier and Spread Spectrum Systems K Fazel and S Kaiser ... guidance systems, and experimental anti-multipath systems [39][43] Spread Spectrum Techniques 31 Table 1-2 Broadcasting standards DAB and DVB-T Parameter DAB DVB-T Bandwidth 1.5 MHz MHz Number of

Ngày tải lên: 09/08/2014, 19:22

... .(2.14) 2.1.4 Spreading Techniques The spreading techniques in MC-CDMA schemes differ in the selection of the spreading code and the type of spreading. As well as a variety of spreading codes, ... multi-carrier spread spectrum, each data symbol is spread over L sub-carriers. In cases where the number of sub-carriers N c of one OFDM symbol is equal to the spreading code length L, the OFDM symbol ... systems with narrowband sub-channels typically use high numbers of sub-carriers and can be efficiently realized by using the OFDM operation. Since each sub-channel is narrowband and spreading is performed

Ngày tải lên: 09/08/2014, 19:22

... MC-CDMA systems with the soft IC detection technique out- perform coded OFDM (OFDMA, MC-TDMA) systems and MC-CDMA systems with MLSE/MLSSE. The performance of the initial stage with soft IC is ... spectral efficiency of MC-CDMA with soft IC and of OFDM (OFDMA, MC-TDMA) versus the SNR is shown in Figure 2-19. The results are given for the code MC-CDMA 79 soft IC, initial detection soft IC, 1 iteration ... with soft IC already after the first iteration. The FEC coded BER versus the SNR per bit for different symbol mapping schemes in MC-CDMA systems with soft IC and in OFDM (OFDMA, MC-TDMA) systems

Ngày tải lên: 09/08/2014, 19:22

... currently part of several high-rate wireless LAN standards, e.g., IEEE 802.11a/g/h, ETSI HIPERLAN/2, and MMAC, and is also part of the IEEE 802.16a and draft ETSI- HIPERMAN WLL standards [4][5][10][11] ... a performance comparison between MC-CDMA and OFDMA for the downlink and between SS-MC-MA and OFDMA for the uplink. The transmission bandwidth is 2 MHz and the carrier frequency is 2 GHz. The guard ... and A/D Conversion and. .. on Multi- Carrier Spread- Spectrum (MC-SS’97), Oberpfaffenhofen, Germany, pp 49 56 , April 1997 References 113 [19] Kaiser S and Fazel K., “A flexible spread

Ngày tải lên: 09/08/2014, 19:22

... mobile radio systems is defined The frequency band has a bandwidth of B = 2 MHz and is located at a carrier frequency... in MIMO-OFDM Systems The basic concept of applying OFDM in multiple ... number of sub-carriers per OFDM symbol and N s is the number of OFDM symbols per OFDM frame. The estimates of the discrete channel transfer function H n,i are denoted as ˆ H n,i . An OFDM frame ... .64 ) 1 2fD,filter Ts (4 .65 ) Nf and in the... frequency of fc = 1.8 GHz The OFDM operation and its inverse are achieved with an IFFT and FFT, respectively, of size 512 The considered multi-

Ngày tải lên: 09/08/2014, 19:22

... Multiplexing: OFDM-CDM OFDM-CDM is a multiplexing scheme which can better exploit diversity than conven- tional OFDM systems. Each data symbol is spread over several sub-carriers and/ or several OFDM symbols, ... Demapping, and Equalization 167 123 10 −5 10 −4 10 −3 10 −2 10 −1 10 0 4 BER 5 E b /N 0 in dB 678 OFDM-CDM, CC OFDM, CC OFDM, TC, I = 256 OFDM, TC, I = 1024 Figure 4-43 Performance of OFDM-CDM ... versus OFDM with Turbo codes and interleaver size 256 and 1024, respectively MC-CDMA and SS-MC-MA can be considered special cases of OFDM-CDM. In MC- CDMA, CDM is applied for user separation and

Ngày tải lên: 09/08/2014, 19:22

... of the application of MC-CDMA for a future 4G cellular mobile radio system is given. Then, the OFDM-based HIPERLAN/2 and IEEE 802.11a standards are 198 Applications studied. The application of ... low data rate. 3G systems provide similar mobility as Multi-Carrier and Spread Spectrum Systems K. Fazel and S. Kaiser  2003 John Wiley & Sons, Ltd ISBN: 0-470-84899-5 196 Applications Tabl ... rate and channel conditions the best combination of FEC, modulation scheme, and the number of time slot is allocated. The main objective is to offer the best trade-off between data rate and coverage,

Ngày tải lên: 09/08/2014, 19:22

... channel. The time duration of a transmission frame depends on the number of consecutive OFDM symbols and on the time duration of the OFDM symbol. The time duration of an OFDM symbol depends on — ... combinations of time and frequency diversity, thereby providing various degrees of robustness, burst duration and a wide range of bit rates to the system. Each burst structure makes use of a set of sub-carriers ... consists of a set of OFDM symbols which contain several data sub-channels, a null symbol and a series of synchronization/ranging symbols; — TF2: The second frame type is made up of a set of general

Ngày tải lên: 09/08/2014, 19:22

... new technologies and standards. Therefore, SDR plays an important role for the success and penetration of 4G systems. Software-Defined Radio 257 A set of examples of the current standards for cellular ... future standards in a common platform is one of the major goals of the next generation (4G) of wireless systems. Hence, a fast adaptation/integration of existing systems to emerging new standards ... broadband WLAN and WLL standards support multi-carrier transmission (OFDM). For standards beyond 3G we may expect that a combination of CDMA with a multi- carrier (OFDM) component is a potential candidate.

Ngày tải lên: 09/08/2014, 19:22

... determinants of performance, adaptation, and change Conservation of resources theory In contrast to other resources theories, conservation of resources (COR) theory is of particular interest in understanding ... health systems and offers support for the notion that resources are critical for adaptation and change (i.e., COR theory principle one) For Summary COR-KT theory may offer promise for understanding ... complexity of the health systems environment, the theory development and research findings should stimulate a better understanding of the effect of resource limitations on research use and generate

Ngày tải lên: 10/08/2014, 10:23

... 2.16 Interpolation for start-up and offset modes Y Offset mode Tool center path R : Tool offset : Transition point R Center of offset circle Center of circle Offset cancel mode R Programmed path ... rotating and mathematical calculations for acceleration control and interpolation of lines, circles and parabolae Therefore, the NCK unit has the task of being in charge of the servo and driving ... the “offset” and B in Fig 2.15 is an offset path The code G41 commands toolradius compensation to the left of the tool movement direction, G42 commands toolradius compensation to the right of the

Ngày tải lên: 11/08/2014, 20:21

... system is the soft- ware module of the NCK unit that interprets the part program consisting of G&M- code commands and related addresses such as S, T, and F. The interpreter consists of a parser, ... displacement and the variables A and B denote... radius of the circle, and the variables P1 and P2 give the center position when the start point of the circle is the origin of the coordinate ... understand the structure of a part program and the commands used therein In a CNC system, various coordinate systems, such as the machine coordinate system, workpiece coordinate system, and

Ngày tải lên: 11/08/2014, 20:21

... dedicated to the application of migration matrices in the process of calibration, valuation, and pricing of these products. 1.7 Chapter Outline Chapters 2, 3, and 4 provide a rather broad view and introduction ... Types of Rating Systems Recently, there has been quite some literature dealing with the philoso- phy, dynamics, and classification of different types of rating systems (see, e.g., Altman and Rijken ... through the application of standard supervisory rules. The differentiated levels of LGD are based upon the characteristics of the underlying transaction, including the presence and the type of collateral....

Ngày tải lên: 22/03/2014, 23:20

... multi-carrier spread spectrum systems. We hope that this book will contribute to a better understanding of the principles of multi-carrier and spread spectrum and may motivate further investigation into and development ... Multi-Carrier and Spread Spectrum Systems xiv Preface and DLR on the design of a future broadband air interface or the EU-IST MATRICE, 4MORE and WINNER projects, and especially the NTT-DoCoMo ... general overview of the spread spectrum technique, especially DS-CDMA, is given and examples of potential applications for OFDM and DS-CDMA are analyzed. This introduction is essential for a better understanding...

Ngày tải lên: 02/03/2013, 16:58

... both the real and imaginary parts of are independent of both the real and imaginary parts of unless and Thus, the likelihood function of the observation vector y is the product of the densities ... capabilities of spread- spectrum communication systems. Although direct-sequence systems greatly suppress interference, practical systems require channel codes to deal with the residual interference and ... decoding of each test pattern and the discarding of decoding failures generate the candidate codewords. The decoder selects the candidate codeword with the largest metric. The quantization of soft-decision...

Ngày tải lên: 20/01/2014, 06:20