Apparatus and method for optimal frequency planning in frequency division multiplexing transmissions
US5295138A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1992 |
| Grant date | Mar 15, 1994 |
| Priority date | — |
| Expiry date | Apr 21, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q11/02
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for operating a frequency division multiplexing (FDM) transmitter within a common communication channel is disclosed. The carrier frequency for each separate channel is adjusted for minimizing intermodulation interference. The system randomly allocates each separate channel within the available bandwidth to provide an initial set of separate channel allocation and corresponding carrier frequencies. Thereafter carrier to intermodulation ratio (C/IM) on each channel is measured and the worst channel with the lowest carrier to intermodulation ratio (C/IM) is removed. The system then repeatedly inserts a channel in available unoccupied bandwidth to produce the largest minimum carrier to intermodulation ratio (C/IM). The deletion and insertion continues until no improvement in minimum carrier to intermodulation ratio (C/IM) can be achieved for said random allocation of separate channels. The selected set of separate channel allocations is further fine-tuned by deleting the worst channel with minimum carrier to intermodulation ratio (C/IM) and deleting one other channel from said separate channel allocations to provide a particular dual channel deletion. The system…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.