Method and Entity in TDD Radio Communications

Abstract

Embodiments provides a radio network entity and the method thereof for improving filtering performance in a time division duplexing radio communication system, the radio network entity comprises a first filter which is configured to perform a first type of filtering for a signal to be transmitted to or received from a device in the radio communication system through a radio interface, with a common filtering requirement for transmitting and receiving fulfilled a second filter, which is configured to perform a second type of filtering for the signal to be transmitted to the device, with additional filtering requirement for transmitting besides the common filtering requirement fulfilled and a third filter, which is configured to perform a third type of filtering for the signal received from the device with additional filtering requirement for receiving besides the common filtering requirement fulfilled.

1 .- 16 . (canceled) 
     
     
         17 . A radio network entity for improving filtering performance in a time division duplexing, TDD, radio communication system, comprising:
 a first filter, configured to perform a first type of filtering for a signal to be transmitted to, or received from a device in the radio communication system through a radio interface, with a common filtering requirement for transmitting and receiving fulfilled;   a second filter, configured to perform a second type of filtering for the signal to be transmitted to the device, with additional filtering requirement for transmitting besides the common filtering requirement fulfilled; and   a third filter, configured to perform a third type of filtering for the signal received from the device, with additional filtering requirement for receiving besides the common filtering requirement fulfilled,   wherein a frequency attenuation of the second filter is different from a frequency attenuation of the third filter, a characteristic of the second filter is a characteristic that provides an additional attenuation only required in a transmission path, and a characteristic of the third filter is a characteristic that provides an additional attenuation only required in a reception path.   
     
     
         18 . The entity of  claim 17 , further comprising:
 a bypasser, configured to provide a bypass route to bypass the third filter for the signal received from the device;   an interference detector, configured to detect interferences received; and   a controller, configured to control the bypasser to provide a filtering route including the third filter when the interference detector detects interferences, and to control the bypasser to provide the bypass route when the interference detector does not detects interferences.   
     
     
         19 . The entity of  claim 18 , wherein the bypasser comprises a first multipath switch and a second multipath switch, wherein the bypass route is activated with a first path of the first multipath switch connected with a first path of the second multipath switch, and the filtering route is activated with a second path of the first multipath switch connected with an input of the third filter, and a second path of the second multipath switch connected with an output of the third filter. 
     
     
         20 . The entity of  claim 18 , wherein the bypasser comprises a first voltage control diode, a second voltage control diode and a third voltage control diode, with the second voltage control diode and the third voltage control diode connected with the input and output of the third filter respectively, and then connected with the first voltage control diode in parallel. 
     
     
         21 . The entity of  claim 18 ,
 wherein the interference detector further comprises:
 a detection filter configured to couple to a radio interface and obtain the interferences when the radio interface is not performing transmission, and 
 a power detector configured to determine power level of the interferences; and the controller is further configured to: 
   activate the bypass route if the power level is lower than a predetermined threshold, and activate the filtering route if the power level is not lower than the predetermined threshold.   
     
     
         22 . The entity of  claim 18 , further comprising:
 a gain compensator configured to perform gain compensation between the bypass route and the filtering route,   wherein the controller is further configured to notify the gain compensator of the activating of the bypass route and the filtering route.   
     
     
         23 . The entity of  claim 18 , further comprising:
 a low noise amplifier configured to perform low noise amplifying for the signal received from the device before performing the third type of filtering for it, or before routing it through the bypass route.   
     
     
         24 . The entity of  claim 17 , wherein the radio network entity is a user equipment, UE, or a radio base station, RBS, in the TDD radio communication system, or is an apparatus internal or external to any of the UE or the RBS. 
     
     
         25 . A method for a radio network entity for improving filtering performance in a time division duplexing, TDD, radio communication system, comprising:
 performing a first type of filtering for a signal to be transmitted to, or a signal received from a device in the radio communication system through a radio interface, with a common filtering requirement for transmitting and receiving fulfilled;   performing a second type of filtering for the signal to be transmitted to a device in the radio communication system through a radio interface, with additional filtering requirement for transmitting besides the common filtering requirement for transmitting and receiving fulfilled; and   performing a third type of filtering for the signal received, with additional filtering requirement for receiving besides the common filtering requirement fulfilled,   wherein a frequency attenuation of the second type of filtering is different from a frequency attenuation of the third type of filtering, a characteristic of the second type filtering is a characteristic that provides an additional attenuation only required in a transmission path, and a characteristic of the third type of filtering is a characteristic that provides an additional attenuation only required in a reception path.   
     
     
         26 . The method of  claim 25 , further comprising:
 detecting interferences received; and   wherein the performing the third type of filtering for the signal received is done when the interferences is detected.   
     
     
         27 . The method of  claim 26 , wherein the detecting interferences received further comprises:
 obtaining the interferences when a radio interface is not performing transmission, and   determine power level of the interferences;   and performing the third type of filtering further comprises:   if the power level is not lower than a predetermined threshold, performing the third type of filtering.   
     
     
         28 . The method of  claim 26 , further comprising:
 notifying performing or not performing the third type of filtering for the purpose of gain compensation;   performing gain compensation between a signal with and a signal without the third type of filtering being performed.   
     
     
         29 . The method of  claim 26 , further comprising:
 performing low noise amplifying for the signal received before performing the third type of filtering.   
     
     
         30 . The method of  claim 25 , wherein the radio network entity is a user equipment, UE, or a radio base station, RBS, in the TDD radio communication system, or is an apparatus internal or external to any of the UE or the RBS.