| 摘要 |
<p>A method of transmitting and receiving a spread spectrum signal, wherein a product of a lower bit rate signal and a second PN-code equals the bit rate of of a higher bit rate signal, and wherein a first PN-code sequence is used to spread said product or a higher bit rate signal to a predetermined output chip rate signal which is transmitted. At a receiver the spread spectrum signal is received and demodulated and in a first operation the demodulated signal is correlated with the first PN-code sequence (48) and in a second operation the output (56) from the first mentioned correlating step (42) is correlated with the second PN-code sequence (62). If a strong correlation peak is detected in the output of the first operation and no correlation peak is detected in the output of the second operation it is treated as a higher bit rate (LBR) signal but if at least a weak correlation peak is detected in the output of the first operation and a strong correlation peak is detected in the output of the second operation it is treated as a lower bit rate (LBR) signal.</p> |
