DOWNLINK CONTROL CHANNEL STRUCTURE IN A MOBILE COMMUNICATION SYSTEM AND A TIME-CODE ALLOCATING METHOD USING THE SAME, PARTICULARLY FOR ENHANCING EFFICIENCY OF TRANSMISSION AND ALLOCATION OF A CODE CHANNEL AND MAINTAINING A LOW PAR WHILE SUPPORTING VARIOUS TRANSMISSION RATES BY EXPANDING A HADAMARD CODE IN SYLVESTER METHOD

摘要

PURPOSE: A downlink control channel structure in a mobile communication system and a time-code allocating method using the same, particularly for enhancing efficiency of transmission allocation of a code channel and maintaining a low PAR while supporting various transmission rates by expanding a Hadamard code in Sylvester method, are provided to flexibly allocate signaling information to a control channel by combining merits of time-division multiplexing and code-division multiplexing. CONSTITUTION: A TTI(Transmission Time Interval) is divided into the M number of sections to obtain a basic allocation unit of a control channel. A length of the unit channel is determined according to a length of Hadamard code which makes a reference of initial generation. In this case, the Hadamard code makes the reference of the initial generation in order to enhance efficiency of transmission and allocation, which is defined as a basic Hadamard code. If the basic Hadamard code is too short, the total number of usable orthogonal codes can be limited, whereas if the basic Hadamard code is too long, orthogonality can be broken according to characteristics of a transmission channel. Thus, the Hadamard code should be allocated in a suitable length according to a structure of a system and a service environment. In a system using a physically shared channel as a control channel for transmitting signaling information, one shared channel is simultaneously divided to orthogonal codes of time and symbol level by using a unit channel.