Equalizer training in a radiotelephone system
AssigneeTelefonaktiebolaget L M Ericsson
InventorsTomas Backstrom, Torbjorn Ward, Gustav Larsson
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Abstract
Reception of a transmission in a radiotelephone system including an equalizer is improved by training the equalizer using a synchronization portion of the transmission having a data pattern chosen for its correlation properties and retraining the equalizer using a portion of the transmission transmitted for a different purpose. In particular, the portion of the transmission transmitted for a different purpose may be the digital verification color code transmitted during each burst in a digital cellular mobile radiotelephone system. Reception quality is increased by training the equalizer at more frequent intervals without increasing transmission overhead.
Claims17
In a digital cellular radiotelephone system having a base station and a mobile station exchanging communications bursts of a specified format, one of said base station and said mobile station having equalizer means for reducing inter-symbol interference during said communications bursts, a method of further reducing said inter-symbol interference, comprising the steps of:
- training said equalizer means using a known synchronization pattern occurring at the beginning of said specified format;
- and
- retraining said equalizer means during said communications bursts using a second known pattern provided according to said specified format, said second known pattern having an additional function besides retraining, wherein said second known pattern is a symbol field which is different from one base station to another and is known and constant during a transmission between said mobile station and said base station.
In a digital cellular radiotelephone system having a base station and a mobile station exchanging communications bursts of a specified format, one of said base station and said mobile station having equalizer means for reducing inter-symbol interference during said communications bursts, an apparatus for further reducing said inter-symbol interference, comprising:
- means for training said equalizer means using a known synchronization pattern occurring at the beginning of said specified format;
- means for retraining said equalizer means during said communications bursts using a second known pattern provided according to said specified format, said second known pattern having an additional function besides retraining;
- and
- means for inserting said second known pattern in each communications bursts during a particular call.
The apparatus of claim 10 wherein said second known pattern distinguishes a traffic channel carrying said particular call from other traffic channels in said system.
The apparatus of claim 11 wherein said second known pattern is a coded digital verification color code.
A method of improving the reception of a transmitted signal in a radiotelephone system including an equalizer, comprising the steps of:
- training said equalizer using a synchronization portion of said transmission having a data pattern chosen for its correlation properties;
- and
- retraining said equalizer using a portion of said signal, said signal having an additional function besides retraining, wherein said portion of said signal is a symbol field which is different from one base station to another and is known and constant during the transmission.
An apparatus for improving reception of a transmitted signal in a radiotelephone system including an equalizer comprising:
- means for training said equalizer using a synchronization portion of said transmission having a data pattern chosen for its correlation properties;
- and
- means for retraining said equalizer using a portion of said signal, said signal having an additional function besides retraining, wherein said portion of said signal is a symbol field which is different from one base station to another and is known and constant during the transmission.
Dependencies are inferred from the claim text.