Digital radio receiver which detects when a portion of a burst is stolen for a control message
US5499246A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 28, 1992 |
| Grant date | Mar 12, 1996 |
| Priority date | — |
| Expiry date | Sep 28, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W36/00
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of receiving data transmitted in a burst-mode radio communications such as GSM. Prior to transmission a set of first data elements (bits) relating to a first message which may be associated with a first channel type (e.g. a traffic channel (TCH) in GSM) has selected bits substituted or "stolen" by data elements (bits) relating to a second message which may be associated with a second channel type (e.g. a fast associated channel FACCH in GSM). The data elements relating to the first and second messages are interleaved over the same or a different number of bursts. In a normal GSM traffic burst two single-bit flags are set to `1` to indicate respectively when the even bits or the odd bits of the burst have been stolen for FACCH data. A detector (5) is used to monitor the flags from the same number of bursts over which the FACCH is interleaved. In order to improve the chance of detecting a FACCH in noisy conditions a majority-vote circuit (9) is employed whereby a FACCH decode is initiated if the number of detected flags set to `1` exceeds a threshold value. Specifically, in the case of FACCH, the threshold value may be 5-8, i.e more than half the number of bursts over which …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.