Broadcast superframe with variable reuse and interference levels for a radio communications system

Abstract

A method and apparatus are provided to enhance the efficiency of reuse of a broadcast channel. In one embodiment, the invention includes sending a first burst of a broadcast channel from a broadcast channel radio subject to a first reuse factor, and sending a second burst of the broadcast channel from the broadcast channel radio subject to a second reuse factor. In another embodiment, the invention includes broadcast channel structure with a primary segment having a first reuse factor, a plurality of secondary segments having a second reuse factor greater than the first reuse factor.

1 . A method comprising:
 sending a first burst of a broadcast channel from a broadcast channel radio subject to a first reuse factor; and   sending a second burst of the broadcast channel from the broadcast channel radio subject to a second reuse factor.   
   
   
       2 . The method of  claim 1 , wherein the first reuse factor is associated with a first level of interference from other broadcast channel radios and the second reuse factor is associated with a second lower level of interference from other broadcast channel radios. 
   
   
       3 . The method of  claim 1 , wherein the first burst is sent in a first slot of a repeating frame and the second burst is sent in a second slot of the repeating frame. 
   
   
       4 . The method of  claim 3 , wherein the repeating frame comprises a third slot, the method further comprising not sending a burst of the broadcast channel during the third slot. 
   
   
       5 . The method of  claim 3 , wherein the slots are synchronized between other broadcast channel radios after a common timing reference. 
   
   
       6 . The method of  claim 5 , wherein the common timing reference comprises a satellite timing signal. 
   
   
       7 . The method of  claim 1 , wherein the second burst comprises a first segment using a first set of spatial parameters, a second segment using a second set of spatial parameters, and a third segment using the first set of spatial parameters. 
   
   
       8 . The method of  claim 7 , wherein the first, second and third segments of the burst are transmitted consecutively. 
   
   
       9 . The method of  claim 7 , wherein the spatial parameters comprise relative phases and amplitudes across elements of an antenna array. 
   
   
       10 . The method of  claim 1 , wherein the first burst is for signal acquisition by receiving terminals and the second burst is for transmitting data regarding a particular transmitting terminal. 
   
   
       11 . The method of  claim 1 , wherein the first burst contains timing data and the second burst contains data regarding a particular terminal. 
   
   
       12 . The method of  claim 1 , further comprising sending a third burst having a reuse of one and wherein the first burst contains frequency synchronization bits and the third burst contains timing synchronization bits. 
   
   
       13 . The method of  claim 1 , wherein the first and second bursts are sent on the same channel with a time interval in between the bursts. 
   
   
       14 . A cellular base station comprising:
 a timing reference to synchronize transmissions with other base stations;   a processor to generate a broadcast channel frame, the frame comprising at least two bursts; and   a transmitter to send a first burst of the broadcast channel subject to a first reuse factor, and a second burst of the broadcast channel subject to a second reuse factor.   
   
   
       15 . The base station of  claim 14 , wherein the timing reference comprises a satellite timing signal receiver. 
   
   
       16 . The base station of  claim 14 , wherein the first reuse factor is associated with a first level of interference from other base stations and the second reuse factor is associated with a second lower level of interference from other base stations. 
   
   
       17 . The base station of  claim 14 , wherein the primary segment is for signal acquisition by receiving terminals and the secondary segments are for transmitting data regarding a particular transmitting terminal. 
   
   
       18 . The base station of  claim 14 , wherein the primary segment contains timing data and the secondary segments contain data regarding a particular terminal. 
   
   
       19 . The base station of  claim 14 , wherein the processor generates a frame comprising a third burst and wherein the transmitter sends the third burst subject to a reuse of one, the first burst containing frequency synchronization bits and the third burst containing timing synchronization bits. 
   
   
       20 . The base station of  claim 14 , wherein the transmitter sends the first and second bursts on the same channel with a time interval in between the bursts.