Initial Access Channel for Scalable Wireless Mobile Communication Networks

Abstract

Physical layer structures and access schemes for use in such networks are described and in particular initial access channel (IACH) structures are proposed. A spectrum efficient downlink (DL) IACH design supports different types of User Equipment (UE) capabilities and different system bandwidths. An IACH includes the synchronization channel (SCH) and broadcast-control channel (BCH). A non-uniform SCH for all system bandwidths is provided, as well as scalable bandwidth BCH depending on system bandwidth. An initial access procedure is provided, as well as an access procedure.

1 . A method of transmitting an access channel in a network having a system bandwidth, the access channel comprising a first channel and a second channel, the method comprising:
 transmitting the access channel using a bandwidth less than the system bandwidth.   
     
     
         2 . The method of  claim 1  wherein the first channel is a Synchronization Channel (SCH). 
     
     
         3 . The method of  claim 1  wherein the second channel is a Broadcast-control Channel (BCH). 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 1 , wherein when the system bandwidth is 20 MHz, a plurality of first channels are repeated within the system bandwidth between guard bands adjacent to each first channel. 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . The method of  claim 1 , further comprising transmitting an Extended Synchronization Channel (Extended SCH) of variable bandwidth up to the remainder of the system bandwidth. 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . The method of  claim 1 , further comprising transmitting an Extended Broadcast-control Channel (Extended BCH) of variable bandwidth up to the remainder of the system bandwidth. 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . A method of transmitting a communication signal, the communication signal comprising one or more frames being of the type that are regularly repeated, each frame comprising a plurality of time slots, each time slot comprising one or more OFDM symbols, the method comprising:
 inserting common pilot symbols in predetermined OFDM symbols;   inserting a SCH over some or all of the predetermined OFDM symbols;   transmitting the communication signal.   
     
     
         16 . The method of  claim 15  wherein the SCH comprised comprises a first Secondary cell specific Synchronization Channel (SSC). 
     
     
         17 . The method of  claim 15  wherein the SCH comprises a Primary Synchronization Channel (PSC) inserted into the second-to-last time slot of the frame. 
     
     
         18 . The method of  claim 15  wherein the SCH comprises a Broadcast-control channel inserted into the last OFDM symbol of the last time slot of the frame. 
     
     
         19 . The method of  claim 18  wherein a second SSC is inserted into an OFDM symbol, other than the first OFDM symbol, of each time slot of the frame. 
     
     
         20 . The method of  claim 19  wherein the second SSC is inserted into the fourth OFDM symbol of each time slot of the frame. 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . A method for decoding a BCH from a diversity transmitted signal comprising:
 receiving a plurality of time domain OFDM signals from a plurality of transmit antennas to provide a received signal;   decoding from the received signal a basic BCH without any information regarding the number of transmit antennas; and,   decoding from the received signal an Extended BCH.   
     
     
         25 . The method of  claim 24  wherein the basic BCH is decoded using one of a frequency switched transmit diversity (FSTD) scheme and a cyclic delay diversity scheme (CDD) and the Extended BCH is decoded using one of a FSTD and CDD scheme. 
     
     
         26 . The method of  claim 25  wherein the Basic BCH is decoded using one of a FSTD scheme and the Extended BCH is decoded using a block code based transmit diversity scheme. 
     
     
         27 . A method of a UE performing initial access to a BTS comprising:
 performing initial timing and frequency synchronization based on a basic SCH;   performing initial cell search based on the basic SCH;   detecting the basic BCH;   obtaining system parameters;   decoding a basic BCH and an Extended BCH;   entering a connected mode; and   performing sync tracking and cell search based on both the basic SCH and the Extended SCH.   
     
     
         28 . A base transceiver station in a communication network, the communication network having a system bandwidth, the base transceiver station comprising:
 a processor configured to select a bandwidth for an access channel less than the system bandwidth, and transmit the access channel.   
     
     
         29 . The base transceiver station of  claim 28 , wherein the processor is further configured to transmit an Extended SCH. 
     
     
         30 . The base transceiver station of  claim 28 , wherein the processor is further configured to transmit an Extended BCH.