Random Access Preamble Transmission Design With Multiple Available Random Access Channel Resources

Abstract

A method for use of a RA preamble with multiple available RACH resources is described. The method includes allocating resources including a plurality of RACH resources for a UE. Information that indicates a dedicated preamble and the allocated resources is sent to the UE. The UE receives the information. A response including the dedicated preamble is generated at the UE. The method also includes the UE sending the response over at least two of the allocated resources. In response to receiving at least one response, a message is transmitted to the UE. Apparatus and computer readable media are also described

1 . A method comprising:
 allocating resources comprising a plurality of random access channel resources for a user equipment;   sending information that indicates a dedicated preamble and the allocated resources to the user equipment;   receiving at least one response comprising the dedicated preamble over at least one of the allocated resources; and   in response to receiving the at least one response, transmitting a message to the user equipment.   
     
     
         2 . The method of  claim 1 , further comprising: in response to not receiving the dedicated preamble in one of the at least one of the allocated resources, sending a backoff message to the user equipment. 
     
     
         3 . The method of  claim 1 , where allocating the resources is based at least in part on at least one of link level information and pathloss information. 
     
     
         4 . (canceled) 
     
     
         5 . The method of  claim 1 , further comprising sending instructions to adjust transmission power to use when sending the at least one response. 
     
     
         6 - 7 . (canceled) 
     
     
         8 . A method comprising:
 receiving information that indicates a dedicated preamble and allocated resources comprising a plurality of random access channel resources;   generating a response comprising the dedicated preamble; and   sending the response over at least two of the allocated resources.   
     
     
         9 . The method of  claim 8 , further comprising: in response to receiving a backoff message, calculating a delay time to use when resending the response. 
     
     
         10 . (canceled) 
     
     
         11 . The method of  claim 8 , where sending the response comprises:
 sending the response in a first time domain resource over a first set of frequency domain resources with a first transmission power; and   resending the response in a subsequent time domain resource over a second set of frequency domain resources with a second transmission power,   where the allocated resources comprise the first time domain resource; the subsequent time domain resource; the first set of frequency domain resources and the second set of frequency domain resources.   
     
     
         12 . The method of  claim 11 , where the second set of frequency domain resources comprises less frequency domain resources than the first set of frequency domain resources. 
     
     
         13 . The method of  claim 12 , where the second transmission power provides more power per frequency domain resource of the second set of frequency domain resources than the first transmission power provides per frequency domain resource of the first set of frequency domain resources. 
     
     
         14 . The method of  claim 8 , further comprising setting a transmission power to use when sending the response using the at least two of the allocated resources. 
     
     
         15 . The method of  claim 14 , where the transmission power is set one of evenly for each of a plurality of the at least two of the allocated resources; and based at least in part on channel gain information. 
     
     
         16 . The method of  claim 14 , further comprising receiving instructions to adjust a transmission power to use when sending the at least one response. 
     
     
         17 . The method of  claim 8 , further comprising determining the at least two of the allocated resources to use when sending the response. 
     
     
         18 . (canceled) 
     
     
         19 . An apparatus, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following:
 allocate resources comprising a plurality of random access channel resources for a user equipment;   send information that indicates a dedicated preamble and the allocated resources to the user equipment;   receive at least one response comprising the dedicated preamble over at least one of the allocated resources; and   in response to receiving the at least one response, transmit a message to the user equipment.   
     
     
         20 - 25 . (canceled) 
     
     
         26 . An apparatus, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following:
 receive information that indicates a dedicated preamble and allocated resources comprising a plurality of random access channel resources;   generate a response comprising the dedicated preamble; and   send the response over at least two of the allocated resources.   
     
     
         27 . The apparatus of  claim 26 , where the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to, in response to receiving a backoff message, calculate a delay time to use when resending the response. 
     
     
         28 . (canceled) 
     
     
         29 . The apparatus of  claim 26 , where the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to, where sending the response:
 send the response in a first time domain resource over a first set of frequency domain resources with a first transmission power; and   resend the response in a subsequent time domain resource over a second set of frequency domain resources with a second transmission power,   where the allocated resources comprise the first time domain resource; the subsequent time domain resource; the first set of frequency domain resources and the second set of frequency domain resources.   
     
     
         30 - 34 . (canceled) 
     
     
         35 . The apparatus of  claim 26 , where the at least one memory and the computer program code are also configured to, with the at least one processor, cause the apparatus to determine the at least two of the allocated resources to use when sending the response. 
     
     
         36 - 72 . (canceled) 
     
     
         73 . The method of  claim 1 , where the method is performed by execution of a computer program by a processor. 
     
     
         74 . The method of  claim 8 , where the method is performed by execution of a computer program by a processor.