WCDMA technology and FOMA installation plan

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Principle of CDMA - Frequency allocation - Principle of DSCDMA - Transmit power control Basic WCDMA Transmission Technologies - Twolayer spreading code assignment - InterBS asynchronous mode Characteristics of WCDMA - Statistical Multiplexing effect - MS standby time - Coherent RAKE reception (RAKE time diversity) 3G Roll Out Plan - FOMA service content - 3G Roll out plan

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Nội dung Text: WCDMA technology and FOMA installation plan

WCDMA technology and FOMA installation plan 3rd September, 2002 Network planning Dept. NTT DoCoMo
Today’s Items Principle of CDMA Frequency allocation Principle of DSCDMA Transmit power control Basic WCDMA Transmission Technologies Twolayer spreading code assignment InterBS asynchronous mode Characteristics of WCDMA Statistical Multiplexing effect MS standby time Coherent RAKE reception (RAKE time diversity) 3G Roll Out Plan FOMA service content 3G Roll out plan 2
Frequency Allocation FDMA / TDMA CDMA f1 f1 f1 f1 f2 f2 f1 f1 f3 f3 f1 f1 f1 f1 f1 f1 f1 f1 f2 f2 f2 f1 f1 f1 f3 f3 f3 f1 f1 f1 f1 f1 f1 f1 f2 f2 f1 f1 f3 f3 f1 f1 In case of 3 cell repetition Same frequency in all area. Take care of frequency allocation. 3
Principal Diagram B(5MHz) B(5MHz) W W W Channel Data Data Channel Filter Coding Modulation Demodulation Decoding Spreading Code ~ ~ Spreading Code Frequency Frequency Spreading Synthesizer Synthesizer Despreading Chip rate of spread data SF (spreading factor)= Symbol rate of transmitted data 4
Principal Diagram (Waveform of spreading codes in DSCDMA) Transmitted data User 1 sequence 1 1 1 1 Composite signal 1 Spreading code 1 1 1 1 2 2 0 0 0 0 1 1 1 1 User 2 2 2 1 1 1 1 1 Spreading code Recovered transmitted data 1 1 1 1 Integrate sequence for user 1 1 1 1 1 & dump Spreading code 1 1 1 1 1 1 1 1 1 1 1 1 1 receiver User 1 Integration over the symbol length to recover 5
Transmit Power Control Near – far problem despreading MS MS Node B Power control despreading MS MS Node B TPC Minimize Increase is essential the Tx power the system capacity 6
Transmit Power Control Closed loop transmit power control in the Uplink SIR Target SIR Tslot Up Link Transmit power control SIR measurement 1dB step Down Link TPC bit 7
Today’s Items Principle of CDMA Frequency allocation Principle of DSCDMA Transmit power control Basic WCDMA Transmission Technologies Twolayer spreading code assignment InterBS asynchronous mode Characteristics of WCDMA Statistical Multiplexing effect MS standby time Coherent RAKE reception (RAKE time diversity) 3G Roll Out Plan FOMA service content 3G Roll out plan 8
Twolayer Spreading Code Assignment transmission data is spread by scrambling codes and channelization codes. Extremely large number of scrambling code can be used. Scrambling Code Channelization Code 10m sec length 4 chip 　　 | (38,400 chip) X 512 chip Elimination of interference components Increase arising form multiple CH the system capacity 9
How to use (1/2) Down Link Up Link Scrambling Code Channelization Scrambling Code Code MS (A) NodeB MS NodeB Channelization (B) Code 10
How to use (2/2) Summary Down Link Up Link Scrambling Code To identify cells. To identify Users. Code shall be assigned to Code shall be assigned to each cell. each user. Number of Code ; 512 Number of Code ; 2 24 Assignment work by System Assignment work by Designer is required. System Designer is not required. Channelization Code To identify the channels to be To identify the channels to used in a cell. be used in a user. Code shall be assigned to Code shall be assigned to each user. each channel. 11
InterBS Asynchronous mode (1/2) Code Assignment in Downlink comparison between Asynchronous and Synchronous at intercell Outer Timing Source Intercell Asynchronous Intercell Synchronous GPS GPS de de CellC CellC Co Co CellA CellA g g in in bl bl CellB CellB m m Time Shift ra ra Sc Sc n n de atio d e a tio Co eliz Co eliz n n an an Ch Ch A set of Orthogonal MultiSF Code 12
InterBS Asynchronous mode (2/2) Benefit of Asynchronous No need Outer Timing Source. Flexibly implement indoor service in code planning. Available to assign the same channelization code in each cell. In Downlink, easy to assign scrambling code because of many code available as 512. 13
Today’s Items Principle of CDMA Frequency allocation Principle of DSCDMA Transmit power control Basic WCDMA Transmission Technologies Twolayer spreading code assignment InterBS asynchronous mode Characteristics of WCDMA Statistical Multiplexing effect MS standby time Coherent RAKE reception (RAKE time diversity) 3G Roll Out Plan FOMA service content 3G Roll out plan 14
Statistical Multiplexing Effect 2.5 Statistical Multiplexing effect N/c Voice Activity=0.4 10% (C+1)user 1% User #1 2.0 User #2 Outage=0.1% User #3 User #4 User #5 1.5 User #6 User #7 1.0 Active C user OK! 0 50 100 150 200 Capacity C 15
MS Standby Time Low bitrate common PCH PCH control channel ON ON Rx.OFF High bitrate PCH PCH common control channel ON ON Rx. OFF Wideband accelerates the bit rate in the control channel, 16 And make it possible to reduce the rate of intermittent reception.
Coherent RAKE Reception (RAKE time diversity) Narrowband received signal Node B Power Wideband received signal Multipass Delay time MS Estimation filter Recovered Radio transmitted environment data in urban area Coherent Rake Channel combining decoder Rake combiner High efficiency Wideband High resolution 17 of Rake combiner
Delay profile 7.68Mcps 1µs 18
Site Diversity Up Link Down Link RNC Selection RNC Replica combining generating Quality=5 Quality=10 Node B1 Node B2 Node B1 Node B2 MS MS 19
Site Diversity ( Field trial ) 80 Added Akasakasite 60 RSSI (MS) [dBμ] 40 20 Akasakasite Aoyamasite Delete Aoyamasite 0 time 20 E b /I 0 (BTS) [dB] 15 10 5 0 time 20