GLRT approach for performance improvement in practical burst packet acquisition with AGC amplifier

For code-aided burst packet acquisition, the extensively used square-law cross-correlation noncoherent (CCN) detector is generally studied under a fixed-gain (FG) amplifier model. However, in practical communication systems an automatic-gain-control (AGC) amplifier is usually employed. In such a case CCN will significantly deteriorate, because the amplification of noise in hypothesis H 0 is larger than that of noisy signals in hypothesis H 1. To improve detection performance, the generalized likelihood ratio test (GLRT) approach is adopted. Closed-form expressions of false alarm probability (FAP) and detection probability (DP) are derived for CCN and GLRT in both FG and AGC cases. Based on these expressions, GLRT is compared with CCN in terms of both performance and implementation complexity. Results show that although GLRT reveals a slightly poorer performance than CCN in an ideal case that an FG amplifier is used, it achieves a significant and increasing performance superiority over CCN in a practical case that AGC is exploited with an affordable extra hardware cost.