A method of transmitting a frame to a plurality of stations using a plurality of streams in a multiple input multiple output (MIMO) system, comprising: generating a Very High Throughput signal A (VHT-SIG-A) field including common information for the plurality of stations; generating a Very High Throughput signal B (VHT-SIG-B) field, the VHT-SIG-B field including user specific information for each of the plurality of stations; generating the frame including, the VHT-SIG-A field and the VHT-SIG-B field; and transmitting the frame to the plurality of stations on an operating band which includes a plurality of 20 MHz frequency bands, characterized by repetitively transmitting the signal A (VHT-SIG-A) field and the signal B (VHT-SIG-B) field in units of 20 MHz frequency, wherein: the VHT-SIG-B field comprises a first portion of bits, wherein the first portion of bits is repeated in the VHT-SIG-B field; the first portion of bits comprises a length indicator related to a length of the data field; a number of repetitions of the first portion of bits is determined based on the bandwidth of an operating band, the number of repetitions increasing as the bandwidth of the operating band increases; and a first number of 17 or 19 bits representing the length indicator when the operating band is 40MHz and a second number of 19 or 21 bits, respectively, representing the length indicator when the operating band is 80MHz. generating a Very High Throughput signal A (VHT-SIG-A) field including common information for the plurality of stations; generating a Very High Throughput signal B (VHT-SIG-B) field, the VHT-SIG-B field including user specific information for each of the plurality of stations; generating the frame including, the VHT-SIG-A field and the VHT-SIG-B field; and transmitting the frame to the plurality of stations on an operating band which includes a plurality of 20 MHz frequency bands, characterized by repetitively transmitting the signal A (VHT-SIG-A) field and the signal B (VHT-SIG-B) field in units of 20 MHz frequency, wherein: the VHT-SIG-B field comprises a first portion of bits, wherein the first portion of bits is repeated in the VHT-SIG-B field; the first portion of bits comprises a length indicator related to a length of the data field; a number of repetitions of the first portion of bits is determined based on the bandwidth of an operating band, the number of repetitions increasing as the bandwidth of the operating band increases; and a first number of 17 or 19 bits representing the length indicator when the operating band is 40MHz and a second number of 19 or 21 bits, respectively, representing the length indicator when the operating band is 80MHz. the VHT-SIG-B field comprises a first portion of bits, wherein the first portion of bits is repeated in the VHT-SIG-B field; the first portion of bits comprises a length indicator related to a length of the data field; a number of repetitions of the first portion of bits is determined based on the bandwidth of an operating band, the number of repetitions increasing as the bandwidth of the operating band increases; and a first number of 17 or 19 bits representing the length indicator when the operating band is 40MHz and a second number of 19 or 21 bits, respectively, representing the length indicator when the operating band is 80MHz.