| 摘要 |
A wireless star topology communication network is implemented in which a centrally located access point supports a very large number of fixed location nodes distributed over a large metropolitan area. Communication is by direct sequence spread spectrum modulating m-ary quadrature amplitude modulation symbols. The access point and all nodes are synchronized using GPS or other means to prevent data collisions. Multiple access is primarily based on signal propagation time between the access point and a node which allows nodes at different ranges to use the same direct sequence code. |
