An orthogonal code-division multiplexing and time-hopping multiple access transmission scheme for UWB communications

We propose an Orthogonal code-division multiplexing and Time-hopping multiple access (OCDM-THMA) transmission scheme for Ultra-wide bandwidth (UWB) communications in a multi-user and multipath environment. The design achieves high data throughput due to the use of the orthogonal code division multiplexing transmission technology for individual users. The data bits from each user are mapped by using the serial-parallel transform, and then are summed and transmitted simultaneously after being modulated by their corresponding orthogonal code sequences. At the receiving side, we employ a Rake-receiver to combat multipath fading. The Bit-error-rate (BER) performance in the presence of Multiple access interference (MAI) is analyzed for multi path channels.