Sökning: "Interference channels"

Visar resultat 6 - 10 av 129 avhandlingar innehållade orden Interference channels.

1. 6. Language Support for Controlling Timing-Based Covert Channels

   Författare :Alejandro Russo; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; information-flow; language-based security; semaphores; non-interference; Haskell; library; concurrency; internal timing covert channel;

   Sammanfattning : The problem of controlling information flow in multithreaded programs remains an important open challenge.A major difficulty for tracking information flow in concurrent programs is due to the internal timing covert channel. LÄS MER

3. 7. Successive Interference Cancellation in DS-CDMA Systems

   Författare :Ann-Louise Johansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; group-wise detection; direct-sequence code division multiple access DS-CDMA ; multiuser detection; multirate schemes; weighted cancellation; successive interference cancellation;

   Sammanfattning : There is every indication that direct-sequence code division multiple access (DS-CDMA) will be one of the multiple access schemes for the third generation wireless mobile systems. CDMA is a flexible multiple access method suitable for supporting many new services (speech, data, video, etc), which are becoming increasingly important for mobile communications. LÄS MER

4. 8. Open Quantum Systems : Effects in Interferometry, Quantum Computation, and Adiabatic Evolution

   Författare :Johan Åberg; Erik Sjöqvist; Sten Lunell; Vlatko Vedral; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Open Systems; Completely Positive Maps; Channels; Decoherence; Quantum Information; Quantum Computing; Adiabatic Approximation; Quantum Search; Time-Complexity; Fysik; Physics; Fysik;

   Sammanfattning : The effects of open system evolution on single particle interferometry, quantum computation, and the adiabatic approximation are investigated.Single particle interferometry: Three concepts concerning completely positive maps (CPMs) and trace preserving CPMs (channels), named subspace preserving (SP) CPMs, subspace local channels, and gluing of CPMs, are introduced. LÄS MER

5. 9. On Soft Decoding and Robust Vector Quantization

   Författare :Mikael Skoglund; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; speech and image coding; intersymbol interference; Rayleigh fading; soft decoding; CDMA; index assignment; Hadamard transform; channel optimized VQ; robust VQ; combined source-channel coding; vector quantization VQ ; noisy channels;

   Sammanfattning : This thesis considers vector quantization for noisy channels. Vector quantization (VQ) is an important technique for block-based source coding, with applications in, e.g., speech and image coding. LÄS MER

7. 10. The Block Error Rate in Block Interference Channels and its Applications to Medium Access Control

   Författare :Arash Tahmasebi Toyserkani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; throughput; wireless sensor networks; TDMA; block fading channels; Block error rate; scheduling; ALOHA; medium access control;

   Sammanfattning : This thesis may be distinguished into two interdependentparts. The first part outlines the outcome of our efforts toconstruct accurate and yet simple models that account for the probability of successful reception of a packet for a wide range of physical layer parameters. LÄS MER