Simplifying decoding of codewords in a wireless communication system

A method and device are described for determining whether or not reserved bits of a field are assigned a function so that the mobile station may easily be adapted to perform enhanced functions. Such a determination enables first generation mobile stations to perform enhanced functions using bits which are initially reserved but may be assigned to service or function in later generations of the protocols. An indication of whether or not the reserved bits have been assigned a function may be sent on a broadcast channel by a usage information element. If the usage information element indicates that the reserved bits have not been assigned any service, such as power control, time alignment or short message services, the reserved bits may be used to enhance functions, such as equalization and synchronization. The method and device may further provide for improved decoding of the coded superframe phase/packet channel feedback (CSFP/PCF) field. Because the superframe phase (SFP) information is known when looking at the remaining bits from the start and end of the broadcast information, the number of possible codewords in the CSFP/PCF field may be reduced in the decoding process. Also, the length of a codeword to be decoded may be reduced based on a usage information element sent on the broadcast channel which indicates whether a reserved bit in the CSFP/PCF field is still reserved. More generally, the block code of any channel coded word, not necessarily packet data, may be effectively reduced based on knowledge of some information in the coded word. Decoding performance is improved by shortening the length of the codewords to be decoded because the shorter codewords are less susceptible to bit errors.