Method and apparatus for reducing phase cancellation in a simulcast paging system
US5913172A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1996 |
| Grant date | Jun 15, 1999 |
| Priority date | — |
| Expiry date | Nov 15, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H20/67
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A transmitter includes a modulator, a power amplifier and a controller to reduce the effects of phase cancellation in a simulcast paging system. The modulator is digitally configurable to modulate according to at least two protocols. The controller configures the modulator for a first protocol and provides to the modulator a signal to be broadcast. The modulator then modulates this signal according to the first protocol and causes the modulator to introduce a random frequency offset within a frequency range predetermined to optimally reduce phase cancellation for the first protocol. When the controller provides a signal to be broadcast according to a second protocol, the controller reconfigures the modulator for the second protocol. In addition the controller causes the modulator to introduce a random frequency offset within a predetermined range to optimally reduce phase cancellation for the second protocol. Because the controller can change the frequency offset on a protocol basis, phase cancellation errors can be optimally reduced for both protocols. In addition, the transmitter can easily be reconfigured to support new protocols as they are developed without changing the existi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.