wideband code division multiple access wcdma or 3gsm handset

Ngày tải lên: 27/06/2014, 14:20

... transmission. THEORY OF CODE DIVISION MULTIPLE ACCESS COMMUNICATION 1 INTRODUCTION TO CELLULAR MOBILE RADIO COMMUNICATION The subject of this book is code division multiple access (CDMA) communi- cations. ... source coding and channel error-correcting coding) and the corresponding signal pro- cessing techniques at the receiver. 1.2 FREQUENCY DIVISION AND TIME DIVISION MULTIPLE ACCESS Multiple access schemes are ... COMMUNICATION Spreader 2 Impulse generator 2 Channel Spreader K Impulse generator K Spreader 1 { u (1) } n Impulse generator 1 Modulator 1 Modulator 2 Modulator K Encoder 1 Encoder 2 Encoder K . . . . { u (2) } { u ( K ) { v (1) } n { v (2) } n { v (1) n { a (1) } n { a (2) } n { a ( K ) } } } } n a (1) s (1) ( t ) s (1) ( t ) s ( K ) ( t ) } n { v (2) n a (2) } n { v ( K ) n { v ( K ) n a ( K ) Figure...

Ngày tải lên: 01/06/2014, 11:27

Ngày tải lên: 22/06/2014, 23:20

Ngày tải lên: 23/06/2014, 01:20

... Europe RACH Random Access CHannel (GSM, UTRA transport channel) RAMA Resource Auction Multiple Access RAN Radio Access Network RAP Random Access Protocol RCMA Reservation -Code Multiple Access RES Reservation ... to assign individual portions of its resources to support multiple communications, basic multiple access techniques (such as frequency-, time-, or code- division multiple access, with FDMA, TDMA, ... mode) NWL Network Layer O ODMA Opportunity Driven Multiple Access OFDM Orthogonal Frequency -Division Multiplexing OSI Open Systems Interconnection OVSF Orthogonal Variable Spreading Factor (UMTS) P P-CCPCH...

Ngày tải lên: 02/03/2013, 16:59

... users in the internetwork cannot forward these documents, do not allow any computers telnet nor FTP access to the Internet. Will new access control list(s) be created or will the current list(s) ... of the routers with access lists, display the access lists with the Boaz#show ip access- lists command. Record the information about one of the access lists. _____________________________________________________________________________________ ... Inbound access list is ________ Interface __________ Outgoing access list is ________ Inbound access list is ________ Interface __________ Outgoing access list is ________ Inbound access...

Ngày tải lên: 18/01/2014, 05:20

... polling access method 12.40 Figure 12.22 Time -division multiple access (TDMA) 12.35 Figure 12.20 Logical ring and physical topology in token-passing access method 12.1 Chapter 12 Multiple Access Copyright ... bands. Note 12.6 Figure 12.4 Procedure for pure ALOHA protocol 12.24 Figure 12.13 Collision and abortion in CSMA/CD 12.38 Figure 12.21 Frequency -division multiple access (FDMA) 12.29 In CSMA/CA, the ... Permission required for reproduction or display. 12.25 A network using CSMA/CD has a bandwidth of 10 Mbps. If the maximum propagation time (including the delays in the devices and ignoring the time...

Ngày tải lên: 16/02/2014, 20:20

... the transmission performance for high communication SNR, but it causes more errors for low SNR. For the transmission schemes using CRC, the BER is even worse b e caus e long codes will reduce the ... suboptimal decentralized estimators in wireless sensor networks over orthogonal multiple- access fading channels in this paper. Considering multiple- bit quantization for digital transmission, we ... Sensor Networks. Lecture Notes in Com- puter Science, vol. 2634, (2003), p p. 162–177 17. M Gastpar, Uncoded transmission is exactly optimal for a simple Gaussian “sensor” network. in 2007 Information...

Ngày tải lên: 18/06/2014, 22:20

... the transmission performance for high communication SNR, but it causes more errors for low SNR. For the transmission schemes using CRC, the BER is even worse b e caus e long codes will reduce the ... modulati on for all codebooks. Because the code length of the uncoded transmission is shorter than that of the coded transmission, the energy to transmit each symbol will be higher for a given ... the redundant observations provided by multiple sensor s . However, their performance degrades dramatically when communication errors cannot be ignored or corrected. On the other hand, various...

Ngày tải lên: 20/06/2014, 04:20

... statistics in the decoded information from the sensors allow for the concatenation of BCH codes [39, 40]in order to decrease the aforementioned intrinsic error floor of single LDGM codes. Extensive ... reduce the error floor inherent to LDGM codes. Inspired by this previous work, in this paper we take a step further by analyzing the performance of concatenated BCH-LDGM codes for encoded data fusion ... errors per decoded block λ motivates the inclusion of an outer sys- tematic BCH code whose error correction capability t is adjusted so as to correct the residual errors obtained in the error...

Ngày tải lên: 21/06/2014, 07:20

... interference on multiple access networks, we propose an analytical framework to characterize partial interference for two representative types of multiple access wireless networks, namely, the ... the original work is properly cited. To determine the capacity of wireless multiple access networks, the interference among the wireless links must be accurately modeled. In this paper, we formalize ... with each other, resulting in performance degradation. Therefore in the study of wireless networks, one important performance measure is the capacity of the network when the effects of interlink interference...

Ngày tải lên: 21/06/2014, 11:20

... of LDGM codes permits to efficiently exploit the intrinsic spatial correlation between the information registered by the sensors, whereas BCH codes are selected to lower the error floor due ... Diversity and Transmit Beamforming” by Di Zheng and Yu-Dong Yao presents a theoretical contribution for the study of classical Slotted ALOHA random access algorithm for multi -access- point diversity ... Networking 2012, 2012:45 doi:10.1186/1687-1499-2012-45 Norman Abramson (norm@alohanet.com) Claudio Sacchi (sacchi@disi.unitn.it) Boris Bellalta (boris.bellalta@upf.edu) Alexey Vinel (vinel@ieee.org) ISSN...

Ngày tải lên: 21/06/2014, 17:20

... the corresponding capacity with L-order receive diversity. 4. CAPACITY ANALYSIS OF A TIME-HOPPING MULTIPLE ACCESS PPM OR PAM UWB SYSTEM With more than one user active in the system, multiaccess interference ... of the multiple- access interference (MAI) [10]. However, for simplicity, an M-ary correlation receiver is typically used even when there is more than one active user. For PAM, only one correlation ... one user is present, the optimal receiver for PPM is a bank of M correlation receivers followed by a detector. When more than one link is active in the multiple- access system, the optimal PPM receiver...

Ngày tải lên: 21/06/2014, 22:20

... that the frame is bit- interleaved prior to the FHSS transmission in order to spread burst errors in the decoder. We consider a multiple- access FHSS network of K users. The frequency band is ... practical for short-delay applications because the performance is not affected significantly by the frame size. In cellular networks, multiple access interference (MAI) may arise when more than one ... codeword given that the all- zero codeword is transmitted. In (6), w d is the number of codewordswithoutputweightd obtained from the weight enumerator of the code [12]. In FHSS systems, the PEP...

Ngày tải lên: 21/06/2014, 23:20

... [5] for multiple- access channels. We will give an achievable rate region for all five side information cases listed in Section 2.4.Twomaincode constructions are used, namely in Theorem 1 for Case ... a multiple- access system,” IEEE Transactions on Information Theory, vol. 34, no. 5, pp. 918–930, 1988. [5] T.M.CoverandJ.A.Thomas,Elements of Information Theory, John Wiley & Sons, New York, ... i.i.d. random codes. Specifically, each user generates a codebook C (i) containing 2 nR i . = SNR r i n i codewords denoted as X (i) 1 , , X (i) SNR r i n i .Each codeword is n-length vector with i.i.d....

Ngày tải lên: 21/06/2014, 23:20

Ngày tải lên: 22/06/2014, 01:20

Ngày tải lên: 22/06/2014, 19:20

Ngày tải lên: 22/06/2014, 19:20

Ngày tải lên: 23/06/2014, 00:20

Ngày tải lên: 23/06/2014, 00:20