Patent ID: 8134945

Claim:
A method for increasing cell capacity through optional signal combining between Relay Stations (RSs) in a cellular system using wired RSs, the method comprising: receiving, by a Base Station (BS), an average Carrier-to-Interference ratio (C/I) value of transmission signals from Mobile Stations (MSs) located inside each coverage area, being fed back from the RSs or the MSs in its corresponding cell; classifying the MSs into two groups according to the C/I value; performing resource allocation satisfying a minimum data rate from a corresponding RS, for MSs belonging to a group having a C/I value greater than a preset threshold .GAMMA. among the classified groups; performing resource allocation by applying an optional signal combining scheme taking into account a combination of two RSs having a highest C/I value, for MSs belonging to a group having a C/I value below the threshold among the classified groups by; applying signal combining of the RS with the highest C/I value and the RS with the second highest C/I value, if α×C k′,n′,s 1 <C k′,n′,s 1,2 is satisfied; and allocating corresponding subchannels only for the RS with the highest C/I value if α×C k′,n′,s 1 <C k′,n′,s 1,2 is not satisfied, wherein α is a parameter related to signal combining condition, an MS having a highest C/I value in a corresponding group is defined as k′, an RS with a highest C/I value and an RS with a second highest C/I value are defined as s 1 and s 2 , respectively, and a subchannel corresponding to a maximum value of transmittable bits among available subchannels n for k′ and s 1 is defined as n′, c k,n,s is defined as a number of transmission bits satisfying a target Bit Error Rate (BER) taking into account a signal level for a subchannel #n that an MS #k has received from an RS #s, and allocating all unallocated subchannels of each individual RS in an order of an MS having a high C/I value among MSs of a corresponding RS until there is no more unallocated subchannel of each RS.