4.Cellular Systems:Multiple Access and Interference Management Wireless F oundations Narrowband (GSM) The total bandwidth is divided into many narrowband channels.(200 kHz in GSM) Users are given time slots in a narrowband channel(8 users) Multiple access is orthogonal:users within the cell never interfere with each other. Interference between users on the same channel in different cells is minimized by reusing the same channel only in cells far apart. 。 Users operate at high SINR regime The price to pay is in reducing the overall available degrees of freedom. Fundamentals of Wireless Communication,Tse&Viswanath 5 4. Cellular Systems: Multiple Access and Interference Management Fundamentals of Wireless Communication, Tse&Viswanath 5 Narrowband (GSM) • The total bandwidth is divided into many narrowband channels. (200 kHz in GSM) • Users are given time slots in a narrowband channel (8 users) • Multiple access is orthogonal: users within the cell never interfere with each other. • Interference between users on the same channel in different cells is minimized by reusing the same channel only in cells far apart. • Users operate at high SINR regime • The price to pay is in reducing the overall available degrees of freedom