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ssrs barcode image PN binary sequence. One element is known as a chip. in Software
PN binary sequence. One element is known as a chip. Reading QR In None Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications. Generating QR Code ISO/IEC18004 In None Using Barcode maker for Software Control to generate, create QR Code 2d barcode image in Software applications. Satellite Access
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Make QRCode In .NET Using Barcode generator for ASP.NET Control to generate, create Denso QR Bar Code image in ASP.NET applications. Generating QR In .NET Framework Using Barcode drawer for .NET Control to generate, create QR image in VS .NET applications. In Fig. 14.33, p(t) is an NRZ binary information signal, and c(t) is a NRZ binary code signal. These two signals form the inputs to a multiplier (balanced modulator), the output of which is proportional to the product p(t)c(t). This product signal is applied to a second balanced modulator, the output of which is a BPSK signal at the carrier frequency. For clarity, it is assumed that the carrier is the uplink frequency, and hence the uplink carrier is described by eU(t) c(t)p(t) cos Make QR Code ISO/IEC18004 In Visual Basic .NET Using Barcode encoder for Visual Studio .NET Control to generate, create QR Code 2d barcode image in .NET applications. Encode Bar Code In None Using Barcode maker for Software Control to generate, create bar code image in Software applications. (14.33) Creating Barcode In None Using Barcode printer for Software Control to generate, create bar code image in Software applications. Draw EAN128 In None Using Barcode creation for Software Control to generate, create UCC  12 image in Software applications. The corresponding downlink carrier is eD(t) c(t)p(t) cos
Create ANSI/AIM Code 128 In None Using Barcode creator for Software Control to generate, create Code 128C image in Software applications. Make Code39 In None Using Barcode printer for Software Control to generate, create Code39 image in Software applications. (14.34) Drawing 2/5 Standard In None Using Barcode creation for Software Control to generate, create Code 2 of 5 image in Software applications. Recognizing Code 3 Of 9 In Java Using Barcode scanner for Java Control to read, scan read, scan image in Java applications. At the receiver, an identical c(t) generator is synchronized to the c(t) of the downlink carrier. This synchronization is carried out in the acquisition and tracking block. With c(t) a polar NRZ type waveform, and with the locally generated c(t) exactly in synchronism with the transmitted c(t), the product c2(t) 1. Thus the output from the multiplier is c(t)eD(t) c2(t)p(t) cos p(t) cos Dt Paint Code39 In Visual Basic .NET Using Barcode encoder for .NET framework Control to generate, create Code 39 Full ASCII image in .NET applications. Code128 Maker In ObjectiveC Using Barcode creation for iPad Control to generate, create Code128 image in iPad applications. (14.35) Code 3 Of 9 Encoder In Visual C# Using Barcode creator for VS .NET Control to generate, create Code 39 Extended image in VS .NET applications. UPCA Encoder In Java Using Barcode generator for Java Control to generate, create UPC Symbol image in Java applications. This is identical to the conventional BPSK signal given by Eq. (10.14), and hence detection proceeds in the normal manner. GS1  12 Generator In Java Using Barcode creation for Java Control to generate, create UCC  12 image in Java applications. Making Matrix Barcode In Visual Basic .NET Using Barcode drawer for .NET Control to generate, create Matrix Barcode image in Visual Studio .NET applications. 14.10.2 The code signal c(t) The code signal c(t) carries a binary code that has special properties needed for successful implementation of CDMA. The binary symbols used in the codes are referred to as chips rather than bits to avoid confusion c(t)p(t)cos
c(t)p(t)cos
p(t) Tx Rx Acquisition and Tracking
p(t)cos
To coherent detector c(t) c(t) A basic CDMA system.
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with the information bits that will also be present. Chip generation is controlled by a clock, and the chip rate, in chips per second, is given by the clock speed. Denoting the clock speed by Rch, the chip period is the reciprocal of the clock speed: Tch 1 Rch (14.36) The waveform c(t) is periodic, in that each period is a repetition of a given sequence of N chips. The sequence itself exhibits random properties, which will be described shortly. The periodic time for the waveform is TN NTch (14.37) The codes are generated using binary shift registers and associated linear logic circuits. The circuit for a threestage shift register that generates a sequence of N 7 chips is shown in Fig. 14.34a. Feedback occurs from stages 1 and 3 as inputs to the exclusive OR gate. This provides the input to the shift register, and the chips are clocked through at the clock rate Rch. The generator starts with all stages holding binary 1s, and the following states are as shown in the table in Fig. 14.34. Stage 3 also provides the binary output sequence. The code waveform generated from this code is shown in Fig. 14.34b. Clock 1 2 3 V t (b) 2 1 1 0 1 0 0 1 1 1 3 1 1 1 0 1 0 0 1 1 Repeat (a) 1 1 0 1 0 0 1 1 1 0 Generation of a 7chip maximal sequence code.
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Such codes are known as maximal sequence or msequence codes because they utilize the maximum length sequence that can be generated. For Fig. 14.34a the maximum length sequence is 7 chips as shown. In general, the shift register passes through all states (all combinations of 1s and 0s in the register) except the allzero state when generating a maximal sequence code. Therefore, a code generator employing an nstage shift register can generate a maximum sequence of N chips, where N 2n 1 (14.38) The binary 1s and 0s are randomly distributed such that the code exhibits noiselike properties. However, there are certain deterministic features described below, and the codes are more generally known as PN codes, which stands for pseudonoise codes. 1. The number of binary 1s is given by No. of 1s 2 2 (14.39) and the number of binary 0s is given by No. of 0s 2 2
(14.40) The importance of this relationship is that when the code uses V volts for a binary 1 and V volts for a binary 0, the dc offset is close to zero. Since there is always one more positive chip than negative, the dc offset will be given by dc offset V N (14.41) The dc offset determines the carrier level relative to the peak value; that is, the carrier is suppressed by amount 1/N for BPSK. For example, using a code with n 8 with BPSK modulation, the carrier will be suppressed by 1/255 or 48 dB. 2. The total number of maximal sequences that can be generated by an nstage shift register (and its associated logic circuits) is given by Smax (N ) n (14.42) Here, (N ) is known as Euler s function, which gives the number of integers in the range 1, 2, 3 . . ., N 1, that are relatively prime to N

