AEV Stargate - Features RDS

AEV STARGATE
Futurcom Srl via della Tecnica 35, 40050 Argelato Bologna ITALY
11
Figure 5
The structure of the data signal is shown in fig.5.
Base-band structure of Radiodata
The structural element is the “group” containing 104 bits.
Each group comprises 4 blocks of 26 bits each, of which 16 are information and 10 are for
protection.
Each block is directly identifiable by an 8 bit word which is summed in module-2 with the 10
protection bits.
The transmission is completely synchronous and there are no interruptions between
consecutive groups and blocks.
Each block is protected by a self-synchronizing, compressed, cyclical code (26,16), having the
following properties:
DETECTS ALL SI NGLE AND DOUBLE ERRORS ;
DETECTS ERROR STRI NGS OF UP TO AND I NCLUDI NG 1 0 BI TS ;
DETECTS APPROXI MATELY 9 9 .8% OF ERROR STRI NGS OVER 1 0 BI TS LONG .
The code (26,16) performs well in correcting error strings which occur frequently in in-car
reception.
All error strings of upto 5 bits can be corrected.
It should be noted that the correction of reception errors implies a finite possibility of accepting
as correct, an incorrect message that has not been detected.
There is a choice, therefore, between simple error detection which will not recover the
message and full error correction which will do so.
From the results of reception tests carried out in Sweden, it would seem that the optimum
decoding strategy, both for domestic as well as in-car reception, requires correction of single
errors and adjacent double errors and the detection of long error strings.
The application of the error detection and correction code is however left to the receiver
manufacturer.
Features RDS
The principal features of this encoder are as follows:
· 50 PSN
· 100 AF LISTE
· RS 232 C
· DATE, HOUR and CT
· RADIOTEXT
· TA - PTY - MS
· Fast tuning and switching information
· Traffic Message Channel
· Enhanced Other Network
· Linkage Information
· Lenguage Identification Code
· Extended Country Code
· Application Identifications
· Program Type Name
· 19 KHz Input available on the rear panel