Tài liệu CDMA truy cập và chuyển mạch P6 doc

... we 6 The Spectrally Efficient CDMA Performance 6.1 Overview As we have discussed in Chapter 3, the SS /CDMA Traffic channels are based on a spectrally efficient CDMA (SE -CDMA) . The SE -CDMA is designed to reuse ... is used over all of the beams. Code Cross-correlation for FO/SE -CDMA and MO/SE -CDMA Recall that for the FO/SE -CDMA (and MO/SE -CDMA) system T s = L u T c and T c = L b T cc...

Ngày tải lên: 26/01/2014, 14:20

... module. networks having CDMA access for two-way multimedia services called Cable Switched CDMA (CS /CDMA) (see Chapter 3, Section 3.1). Base Station Switched CDMA (BS /CDMA) In BS /CDMA we consider the ... The exchange node in a SW /CDMA using TMS. 4.2 Switched CDMA (SW /CDMA) Architectures In this section we examine the network and switch architectures in SS /CDMA and SW /CDMA f...

Ngày tải lên: 26/01/2014, 14:20

... access is an orthogonal CDMA scheme (in both uplink and downlink) called Spectrally Efficient Code Division Multiple Access (SE -CDMA) (see Chapters 3 and 6). Each SE -CDMA CDMA: Access and Switching: ... through the switch even 5 The Satellite Switched CDMA Throughput 5.1 Overview As we have discussed in Chapters 3 and 4, the satellite switched CDMA system provides on-board switching wh...

Ngày tải lên: 26/01/2014, 14:20

... sequences. Then we have the conventional asynchronous CDMA, also called direct sequence CDMA (DS /CDMA) . The Orthogonal CDMA Orthogonal CDMA (O -CDMA) is based on binary orthogonal sequences of length ... The multiuser data communications process. GENERALIZED CDMA 3 TDMA G-TDMA DS -CDMA G-PDMA G -CDMA FDMA G-FDMA FH -CDMA Figure 1.2 The G -CDMA as the super-set of the multipl...

Ngày tải lên: 26/01/2014, 14:20

... Theory, Vol. IT-20, May 1974, pp. 397–399. 56 CDMA: ACCESS AND SWITCHING [7] X.D. Lin and K.H. Chang ‘Optimal PN Sequence Design for Quasisyn- chronous CDMA Communication System’ IEEE Trans. on Commun., Vol. ... z 1 · z 2 ···z k The orthogonal matrices H z can be constructed by any method described above. 40 CDMA: ACCESS AND SWITCHING Figure 2.4 Fourier, Hadamard and Karhunen–Loeve orthog...

Ngày tải lên: 26/01/2014, 14:20

... satellite switched CDMA (SS /CDMA) B. The base station switched CDMA (BS /CDMA) CDMA Exchange Node H/EH/E H/E H/E PSTN Coax-cable Network C. The cable switched CDMA (CS /CDMA) H/E:Head-End PSTN: ... Systems.‘S- CDMA as a High-Capacity Upstream Physical Layer’ IEEE802.14a/98-016, June 15 1998. 58 CDMA: ACCESS AND SWITCHING CDMA Exchange Node RDP RDP RDP RDP RDP RDP SS /CDMA A....

Ngày tải lên: 26/01/2014, 14:20

... and Synchronization 7.1 Overview As we have described in Chapters 3 and 6, the SS /CDMA uses orthogonal CDMA in both uplink and downlink. The orthogonal CDMA can reject the interference between the user traffic channels ... which synchronous CDMA (orthogonal or quasi-orhtogonal) attempted for use in the uplink or inbound channel. One such example is presented in reference [1], in which s...

Ngày tải lên: 26/01/2014, 14:20

... =1/7, N = 31. 8 Carrier Recovery for ‘Sub-Coherent’ CDMA 8.1 Overview In this chapter we examine possible methods of carrier recovery for the SE- CDMA presented in Chapter 6. In particular, we propose, ... 1999. [12] M. Khairy and E. Geraniotis ‘BER of DS /CDMA Using Symbol-Aided Coherent Demodulation over Rician and Rayleigh Fading Channels’ IEEE ISSSTA, 1998. 188 CDMA: ACCESS AND SWIT...

Ngày tải lên: 26/01/2014, 14:20

... Amplification of Synchronous CDMA 9.1 Overview As we have described in Chapter 3, the SS /CDMA uses orthogonal CDMA for both uplink and downlink transmission. On board the satellite, each CDMA channel is routed ... this study is the satellite switched CDMA system presented in Chapter 3. The link access of the SS /CDMA is based on the SE- CDMA, which is a synchronous CDMA as descri...

Ngày tải lên: 26/01/2014, 14:20

... for ‘Pseudo-Orthogonal’ CDMA 10.1 Overview The CDMA systems presented in the previous chapters were mainly based on the synchronous or orthogonal approach. As we have discussed, orthogonal CDMA achieves ... mobility environment. In such an enviroment, we use ‘Pseudo-Orthogonal’ (PO) CDMA. In the PO -CDMA, capacity (users /CDMA- band) is limited by interference resultingfrom the use of...

Ngày tải lên: 17/10/2013, 22:15