Floating-point scaling technique for sources separation automatic gain control

Abstract

Based on the floating-point representation and taking advantage of scaling factor indetermination in blind source separation (BSS) processing, we propose a scaling technique applied to the separation matrix, to avoid the saturation or the weakness in the recovered source signals. This technique performs an automatic gain control in an on-line BSS environment. We demonstrate the effectiveness of this technique by using the implementation of a division-free BSS algorithm with two inputs, two outputs. The proposed technique is computationally cheaper and efficient for a hardware implementation compared to the Euclidean normalisation.

Keywords:

• floating-point representation
• blind source separation
• automatic gain control
• FPGA implementation

Notes

Note

1. A lower precision (as 16 bits) leads to inefficient separation, while a higher precision (as 48 bits) requires a lot of FPGA resources using the normalisation technique.