Sökning: "turbo codes."

Visar resultat 16 - 20 av 28 avhandlingar innehållade orden turbo codes..

1. 16. Reduced Complexity Techniques for Iterative Decoding

   Författare :Dhammika Bokolamulla; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbo codes; trellis complexity; soft information; trellis pruning; stopping criteria; intersymbol interference; symbol-by-symbol {MAP} detection; reduced-complexity decoding; serially concatenated codes; Iterative detection;

   Sammanfattning : .... LÄS MER

3. 17. On Woven Convolutional Codes

   Författare :Stefan Höst; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Automation; iterative decoding; woven convolutional code; cascaded convolutional code; free distance; convolutional code; active distance; robotics; control engineering; Automatiska system; robotteknik; reglerteknik;

   Sammanfattning : Concatenation of several conventional convolutional encoders is a both powerful and practical method to obtain encoding schemes that are attractive for use in communication systems where very low error probabilities are needed. This thesis is devoted to woven convolutional codes, a construction where the constituent codes are woven together in a manner that resembles the structure of a fabric. LÄS MER

4. 18. Towards a Theory of Codes for Iterative Decoding

   Författare :Michael Lentmaier; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bit error probability; low-density parity-check convolutional code; low-density parity-check code; turbo code; convolutional code; channel coding; iterative decoding; Informatics; systems theory; Informatik; systemteori;

   Sammanfattning : Channel codes in combination with iterative decoding techniques are a both powerful and efficient method to protect data against disturbances in digital communication systems. This thesis deals with various code constructions for block-wise and continuous transmission that have the potential to achieve low bit error rates with iterative decoding, even when operating close to the Shannon limit. LÄS MER

5. 19. Coding and Modulation for Wideband CDMA

   Författare :Ola Wintzell; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbo codes.; Electronics and Electrical technology; channel coding; impulse radio; coordinated transmission; pre-coding; cellular radio capacity; Direct sequence code division multiple access DS-CDMA ; pulse position hopped code division multiple access PPH-CDMA ; Elektronik och elektroteknik; Telecommunication engineering; Telekommunikationsteknik;

   Sammanfattning : Wideband CDMA (Code Division Multiple Access) is one of the key technologies for future mobile communication systems. This thesis studies various coding and transmission methods for wideband CDMA communications. In a cellular environment, the system performance depends on the interference from other cells. LÄS MER

7. 20. Broadband Wireless OFDM Systems

   Författare :Maxime Flament; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; channel model; 4th Generation Wireless 4GW ; shadowing; MMIC; WLAN; scenarios; mobile data; OFDM; turbo codes; propagation; license-exempt bands; coding; 60 GHz channel; broadband wireless; interference; Virtual Cellular Network VCN ; front-end;

   Sammanfattning : While the readiness of the telecommunication market and the users' need for broadband mobile data are not currently noticeable, a set of presented megatrends and scenarios suggest that broadband mobile data access will develop quickly in the next ten years. Identification of the potential frequency bands offering cheap and trouble-free wireless infrastructure is therefore an important step towards the definition of new air interfaces. LÄS MER