Method and apparatus for data communication between a base station and a transponder

Abstract

A method and system for data communication between a base station and at least one transponder via a high-frequency electromagnetic carrier signal onto which information packets are modulated. Each information packet has a header section, a middle section, and a trailer section. The header section can be provided in a forward link of a data communication between the base station and the transponders for controlling data communication. The header section is used in a return link of a data communication in order to transmit information from the transponder to the base station.

1 . A method for wireless data communication between a base station and at least one transponder by a high-frequency electromagnetic carrier signal, the method comprising the steps of: 
 modulating information packets onto the high-frequency electromagnetic carrier signal, each information packet including a header section, a middle section, and a trailer section, the header section being provided in a forward link of a data communication between the base station and the at least one transponder for controlling the data communication,    using the header section in a return link of the data communication in order to transmit information from the at least one transponder to the base station.    
     
     
         2 . The method according to  claim 1 , wherein the information transmitted by the transponder contains operating information of the transponder.  
     
     
         3 . The method according to  claim 2 , wherein the operating information of the transponder contains information on the resolution of the transponder and/or its data transmission rate.  
     
     
         4 . The method according to  claim 2 , wherein the operating information contains information indicating whether the transponder is being operated synchronously or asynchronously at the time.  
     
     
         5 . The method according to  claim 2 , wherein the operating information contains clock information on the transponder's internal clock.  
     
     
         6 . The method according to  claim 2 , wherein the operating information contains information on a modulation of the transponder.  
     
     
         7 . The method according to  claim 1 , wherein the transponder transmits in the header section of the return link at least one reference mark to the base station, the at least one reference mark being analyzed by the base station for further data communication, and wherein, after analysis of this at least one reference mark, the control information in the header section of the forward link is adjusted to the at least one analyzed reference mark.  
     
     
         8 . The method according to  claim 1 , wherein a first reference mark containing clock information is provided in the return link.  
     
     
         9 . The method according to  claim 8 , wherein the first reference mark is transmitted in a first symbol of the header section in the return link.  
     
     
         10 . The method according to  claim 1 , wherein a first reference time is specified in the forward link by which a second reference mark representing a first logical value and a third reference mark representing a second logical value are defined.  
     
     
         11 . The method according to  claim 10 , wherein the first reference time is specified in a second symbol of the header section in the forward link by the base station.  
     
     
         12 . The method according to  claim 1 , wherein a second reference time is specified in the forward link by which clock information and/or frequency information is transmitted to the transponder.  
     
     
         13 . The Method according to  claim 12 , wherein the second reference time is specified by the base station in a fourth symbol of the header section in the forward link.  
     
     
         14 . The method according to  claim 1 , wherein the header section of the forward link and/or of the return link has a total of four symbols.  
     
     
         15 . The method according to  claim 1 , wherein the reference mark, which is provided in the header section of the return link, is defined by at least one amplitude change at a predetermined time point within a symbol.  
     
     
         16 . The method according to  claim 1 , wherein a reference mark is created by switching off a modulation on the transponder side for a predetermined time period.  
     
     
         17 . The Method according to  claim 1 , wherein a first time interval is specified which encompasses, within a symbol, a first time point at which is arranged a first reference mark for a logic zero and a second time point at which is arranged a second reference mark for a logic one.  
     
     
         18 . The method according to  claim 17 , wherein the first time interval is shorter than the duration of the symbol associated with this time interval.  
     
     
         19 . The method according to  claim 1 , wherein, within a symbol, a second time interval is specified which encompasses a first time point at which is arranged a first reference mark for a logic zero, and wherein a third time interval is specified which encompasses a second time point at which is arranged a second reference mark for a logic one.  
     
     
         20 . The method according to  claim 19 , wherein the sum of the second and third time intervals is shorter than the first time interval.  
     
     
         21 . The method according to  claim 20 , wherein the first, second, and/or third time interval is adapted to the resolution of the transponder such that the first, second, and/or third time interval is reduced with increasing resolution of the transponder.  
     
     
         22 . A base station for data communication with at least one transponder, the base station comprising: 
 a transmitting/receiving device for transmitting high-frequency carrier signals to the at least one transponder and for receiving corresponding response signals from the at least one transponder that receives the carrier signals;    a control unit for controlling the data communication with the at least one transponder;    an analysis device, which follows the transmitting/receiving device on a receive side and analyzes a header section of a response signal that is transmitted by the transponder; and    an adjusting device that carries out an adaptation to control information transmitted to the transponder in a header section of a forward link by using the analyzed response signal,    wherein the header section of the response signal that is transmitted by the transponder is used in order to transmit information from a transponder to the base station.    
     
     
         23 . A data communication system comprising: 
 at least one transponder; and    a base station comprising: 
 a transmitting/receiving device for transmitting high-frequency carrier signals to the at least one transponder and for receiving corresponding response signals from the at least one transponder that receives the carrier signals;  
 a control unit for controlling the data communication with the at least one transponder;  
 an analysis device, which follows the transmitting/receiving device on a receive side and analyzes a header section of a response signal that is transmitted by the transponder; and  
 an adjusting device that carries out an adaptation to control information transmitted to the transponder in a header section of a forward link by using the analyzed response signal,  
 wherein the header section of the response signal that is transmitted by the transponder is used in order to transmit information from a transponder to the base station.  
   
     
     
         24 . The data communication system according to  claim 23 , wherein the data communication system is an RFID data communication system.