CDMA 120 – cdmaOne and CDMA2000 Concepts and Terminology phần 5 pot

[...].. .CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80-13321-1 X11 Section 5: Attributes and Techniques Attributes and Techniques of CDMA cdma university A A A A A CDMA 120 Section 5- 1 A A A A A A A A A A A A A A A A A A A A A A A MMT98010137Ag.emf © 2002 QUALCOMM Incorporated 5- 1 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80-13321-1 X11 Section 5: Attributes and Techniques CDMA. .. Define and describe “soft handoff.” z Describe the functioning of a rake receiver z List the transmission rates for cdmaOne vocoders z Estimate the Reverse link capacity of a CDMA system © 2002 QUALCOMM Incorporated 5- 2 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80-13321-1 X11 Section 5: Attributes and Techniques Frequency Reuse cdma university CDMA 120 Section 5- 3 Cell 1 Cell 2 If Cell 1 and. .. frequency plan is required © 2002 QUALCOMM Incorporated 5- 4 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80-13321-1 X11 Section 5: Attributes and Techniques CDMA Frequency Reuse cdma university A A A A A CDMA 120 Section 5- 5 A A A A A A A A A A A A A A A A A A A A A A A MMT98010137Ag.emf Universal Frequency Reuse The principal attribute of a CDMA system is that all subscribers can use the same... Additionally, other factors such as varying path loss and fading result in the need to control the mobile’s transmission power as well © 2002 QUALCOMM Incorporated 5- 6 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80-13321-1 X11 Section 5: Attributes and Techniques cdma university CDMA 120 Power Control (continued) Section 5- 7 • Power Control – Open loop – Fast closed loop MMT98010139Ac.emf The Power... open loop and the closed loop controls can affect the transmission power level on a continual basis as they work together to adjust power © 2002 QUALCOMM Incorporated 5- 8 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80-13321-1 X11 Section 5: Attributes and Techniques Cell B Cell B Cell B CDMA 120 Soft Handoffs cdma university Section 5- 9 Cell A Cell A Cell A MMT98010671Ac.emf Soft Handoffs... complicated reuse patterns are not necessary © 2002 QUALCOMM Incorporated 5- 5 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80-13321-1 X11 Section 5: Attributes and Techniques cdma university Power Control CDMA 120 Section 5- 6 • Near-far Problem • Path Loss • Fading MMT98010138Ac.emf Effective Power Control is Required CDMA will not work without an effective power control, because of the near-far... Incorporated 5- 10 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80-13321-1 X11 Section 5: Attributes and Techniques cdma university CDMA 120 Multipath Section 5- 11 BSC Cell The Mobile can adjust for differing path delays and phase shifts of the different multipath arrivals and then combine the arrivals coherently MMT98010673Ac.emf Better Use of Multipath One of the main advantages of CDMA systems... cellular) and TDMA, which are narrow band systems, cannot discriminate between the multipath arrivals, and resort to equalization to mitigate the negative effects of multipath Due to its wide bandwidth and rake receivers, CDMA uses the multipath signals and combines them to make an even stronger signal at the receivers © 2002 QUALCOMM Incorporated 5- 11 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology. .. level cdmaOne systems use a two-step approach to achieve this: z An original estimate is made by the mobile (open loop power control) z A faster correction is made to this estimate, based on instruction provided to the mobile by the Base Station (closed loop power control) © 2002 QUALCOMM Incorporated 5- 7 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80-13321-1 X11 Section 5: Attributes and. .. reuse, where typically a slot is used only once in a certain geographic area © 2002 QUALCOMM Incorporated 5- 3 CDMA 120 – cdmaOne and CDMA2 000 Concepts and Terminology 80-13321-1 X11 Section 5: Attributes and Techniques Frequency Reuse (continued) cdma university C E B F C E D CDMA 120 Section 5- 4 F B C A G D A D F D B F E E C B C B A G G MMT98010136Ac-rev.emf Frequency Reuse Pattern of 7 A reuse pattern