Sökning: "channel coding"

Visar resultat 16 - 20 av 155 avhandlingar innehållade orden channel coding.

1. 16. 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

3. 17. Joint Source-Channel Coding using Trellis Coded CPM

   Författare :Zihuai Lin; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; iterative decoding; serially concatenated CPM; punctured ring convolutional codes.; trellis coded quantization; turbo codes; turbo trellis coded modulation; soft decoding; ring convolutional coded CPM; continuous phase modulation; Joint source channel coding;

   Sammanfattning : The thesis investigates Joint Source and Channel Coding(JSCC) using combined Trellis Coded Quantization (TCQ) and coded modulation. First we investigate a JSCC scheme using combined TCQ/Trellis Coded CPM (TCQ/TCCPM). Based on the BCJR algorithm for trellis coded CPM, we derive an optimal soft decoding algorithm for the considered systems. LÄS MER

4. 18. On Robust LPC-spectrum Coding and Vector Quantization

   Författare :Roar Hagen; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; robustness against channel noise; LPC-spectrum coding; vector quantization; speech coding; linear mapping of a block code;

   Sammanfattning : Digital speech coding is concerned with representing a discrete-time speech signal with as few bits per second as possible without introducing annoying artifacts in the coded speech. Many modern speech coders are based on Linear Predictive Coding (LPC) which employ a source-filter model for speech production. LÄS MER

5. 19. Channel Shortening in Wireless Communication

   Författare :Sha Hu; Kommunikationsteknologi; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Channel shortening CS ; multi-input multi-output MIMO ; intersymbol interference ISI ; achievable information rate AIR ; partial marginalization PM ; dirty paper coding DPC ; large intelligent surface LIS ; Cramér-Rao lower bound CRLB ;

   Sammanfattning : The concept of Channel Shortening (CS) is a well-known technique that has a rich history over 40 years. CS transfers linear vector channels such as multi-input multi-output (MIMO) and intersymbol interference (ISI) channels into ``shortened'' versions, for the purpose of reducing demodulation-complexity and improving data-transmission performance. LÄS MER

7. 20. Turbo Codes and Channel Estimation in Wireless Systems

   Författare :Bartosz Mielczarek; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; adaptive coding; turbo codes; PSAM; timing offset; BCJR algorithm; synchronization; channel estimation; phase offset; Wiener filters; unequal error protection; OFDM;

   Sammanfattning : This thesis focuses on practical implementation issues of turbo codes with imperfectly estimated fading wireless channels and limited code length. Channel estimation can be divided into estimation of static parameters, such as constant timing and phase offset, and dynamic parameters, such as fading channel amplitudes. LÄS MER