Name
Abstract | ||
|---|---|---|
Medard and Gallager (2002) showed that very large bandwidths on certain fading channels cannot be effectively used by direct sequence or related spread-spectrum systems. This paper complements the work of Medard and Gallager. First, it is shown that a key information-theoretic inequality of Medard and Gallager can be directly derived using the theory of capacity per unit cost, for a certain fourth-order cost function, called fourthegy. This provides insight into the tightness of the bound. Secondly, the bound is explored for a wide-sense-stationary uncorrelated scattering (WSSUS) fading channel, which entails mathematically defining such a channel. In this context, the fourthegy can be expressed using the ambiguity function of the input signal. Finally, numerical data and conclusions are presented for direct-sequence type input signals |
Year | DOI | Venue |
|---|---|---|
2002 | 10.1109/18.992762 | IEEE Transactions on Information Theory |
Keywords | Field | DocType |
Rayleigh channels,broadband networks,channel capacity,code division multiple access,spread spectrum communication,time-varying channels,DS-CDMA,WSSUS fading channel,ambiguity function,broad-band fading channels,capacity,direct sequence systems,direct-sequence type input signals,fourth-order cost function,fourthegy,information-theoretic inequality,input signal,signal burstiness,spread-spectrum systems,wide-sense-stationary uncorrelated scattering fading channel | Ambiguity function,Discrete mathematics,Telecommunications,Fading,Computer science,Communication channel,Algorithm,Burstiness,Broadband networks,Code division multiple access,Channel capacity,Spread spectrum | Journal |
Volume | Issue | ISSN |
48 | 4 | 0018-9448 |
Citations | PageRank | References |
62 | 8.17 | 12 |
Authors | ||
2 | ||
Name | Order | Citations | PageRank |
|---|---|---|---|
| Vijay G. Subramanian | 1 | 406 | 42.43 |
| Bruce Hajek | 2 | 154 | 17.84 |