| 摘要 |
PROBLEM TO BE SOLVED: To provide a wireless local loop apparatus that has an improvement type DAC for executing high-speed, high-resolution D/A conversion, and to provide a corresponding system. SOLUTION: A radio subscriber line terminal (302) and a corresponding WLAN communication system (300) are provided. The radio subscriber line terminal (302) performs a DAC circuit (105). The DAC circuit (105) includes a storage (110) such as a ROM for storing a delta-sigma analog sequence corresponding to all possible values of digital input (106) connected to a plurality of one-bit DACs (120, 122, 124, 126). Each of the DACs (120, 122, 124, 126) is clocked by a multi-phase clock so that each phase added to each of the DACs (120, 122, 124, 126) is delayed mutually merely for an oversampling period. An adder is connected to each of the DACs (120, 122, 124, 126) for summing up each output from each of the DACs (120, 122, 124, 126) for generating analog output.
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