Ch4 tx. chain

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UMTS tx. chain

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Ch4 tx. chain

  1. 1. A/D & Comp. Speech coding Add Channel codingredundancyInterleaving Interleaving Ciphering Ciphering Mapping MappingOVSF codes ChannelizationGold Codes Complex scrambling QPSK Modulation 2
  2. 2.  Cyclic-Redundancy Check (CRC) Coding  Identifies corrupted data  If there is an error, the receiver can request that data be re-sent  For voice data errors, the vocoder discards any bad data Transmitter Original Data CRC Original Data Checksum 100101101010 Generator 100101101010 011010 RF Transmission Path Receiver Received Data Received Checksum If Checksums do not match, 100101001010 011010 there is an error CRC Re-Generated Checksum Generator 011011
  3. 3.  CRC Algorithms  0, 8, 12, 16, or 24 parity bits (determined by upper layers)  g(CRC24) = D24 + D23 + D6 + D5 + D + 1  g(CRC16) = D16 + D12 + D5 + 1  g(CRC12) = D12 + D11 + D3 + D2 + D + 1  g(CRC8) = D8 + D7 + D4 + D3 + D + 1
  4. 4. Xk ZkData InX D D D kRate = X M U X Turbo Data Out Z’k Interleaver D D D
  5. 5. Transmitter Interleaving Matrix Original Data Samples Interleaved Data Samples1 2 3 4 5 6 7 8 9 1 2 3 1 4 7 2 5 8 3 6 9 4 5 6 7 8 9 RF Transmission Path Receiver De- Interleaving Interleaved Data Samples Matrix De-Interleaved Data Samples To Viterbi 1 4 7 2 5 8 3 6 9 1 2 3 1 2 3 4 5 6 7 8 9 decoder 4 5 6 Errors Clustered 7 8 9 Errors Distributed
  6. 6. sin^2(x) = 1/2 - 1/2 cos(2x)cos^2(x) = 1/2 + 1/2 cos(2x)

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