[...]... cellular and PCS spectrum in the United States z Describe the applications of cdmaOne systems © 2002 QUALCOMM Incorporated 2-41 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1 X11 Section 2: Background Comments/Notes © 2002 QUALCOMM Incorporated 2-42 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1 X11 Section 3: Codes in cdmaOne CDMA 120 Codes in cdmaOne cdma university... referred to as Walsh codes © 2002 QUALCOMM Incorporated 3- 6 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1 X11 Section 3: Codes in cdmaOne 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 01 23 0000 0101 0011 0110 0000 0101 0011 0110 0000 0101 0011... subscribers or a mix of fixed wireless and high mobility subscribers © 2002 QUALCOMM Incorporated 2-40 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1 X11 Section 2: Background CDMA 120 Section Review cdma university Section 2-41 SECTION REVIEW • • • • cdmaOne and its Key Standards • • Fast Fading • cdmaOne System Applications Primary Multiple Access Techniques CDMA Network Architecture Digital... and 1 may be viewed as having opposite polarity Thus when the product (XORing in this case) of two binary sequences results in an equal number of 1’s and 0’s, the cross-correlation is zero © 2002 QUALCOMM Incorporated 3- 5 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1 X11 Section 3: Codes in cdmaOne cdma university CDMA 120 Generation of Orthogonal Codes 0 SEED 00 01 • Repeat –. .. cdma university Section 3- 1 (# of agreements - # of disagreements)/N 1 0 -1/N Period of the code 1 PN Chip MMT98010152Ag.emf © 2002 QUALCOMM Incorporated 3- 1 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1 X11 Section 3: Codes in cdmaOne CDMA 120 Section Introduction cdma university Section 3- 2 SECTION INTRODUCTION • • Basics of Spreading Codes • Pseudorandom Noise (PN) Sequences.. .CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1 X11 Section 2: Background cdma university CDMA 120 The PCS CDMA Channel (continued) Section 2 -39 CDMA Channel 50KHz f 25 ~25 Channels MMT98010112Ag.emf Notes The US PCS band is based on 50 KHz channels Thus, a 1.25 MHz CDMA channel is 25 channels (25 x 50 KHz = 1.25 MHz) wide, excluding any required guardband © 2002 QUALCOMM... discussion of codes © 2002 QUALCOMM Incorporated 3- 4 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1 X11 Section 3: Codes in cdmaOne CDMA 120 Orthogonal Codes cdma university Section 3- 5 Orthogonal functions have ZERO CORRELATION Two binary sequences are orthogonal if the process of "XORing" them results in an equal number of 1's and 0's: EXAMPLE: 0000 0101 0101 MMT98010157Ag.emf... Codes cdmaOne systems use two types of code sequences: z Orthogonal sequences (Walsh codes) z Pseudorandom noise (PN) sequences This section examines the basic properties of both codes Note: The CDMA2 000 Overview section will introduce a new type of code, the Quasi-orthogonal code © 2002 QUALCOMM Incorporated 3- 2 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1 X11 Section 3: Codes... 2002 QUALCOMM Incorporated 2 -39 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1 X11 Section 2: Background cdma university Fixed Wireless (Wireless Local Loop) CDMA 120 Section 2-40 MMT98010692Ac.emf Fixed Wireless (Wireless Local Loop, WLL) A cdmaOne system can provide an efficient, cost-effective alternative to the traditional wireline local loop A CDMA- based interface can be used... terrestrial cdmaOne systems are Walsh codes of length 64 z In the Forward CDMA link, Walsh codes are used to separate users In any given sector, each Forward Channel is assigned a distinct Walsh code z In the Reverse CDMA link, the 64 Walsh sequences are used as a signaling set by the Baseband Orthogonal Modulator © 2002 QUALCOMM Incorporated 3- 7 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80- 133 21-1