In this paper, a simple configurable systolic array structure for signal processing is proposed. This array is configurable not only for its dimension, but also for different kinds of signal processing algorithms. The basic connection pattern used is a spiral structure. Through a carefully designed switch, a desired array dimension can be easily configured. The configurability for various kinds of signal processing operations is achieved by designing a simple configurable processing element whose configuration is set by a control signal. This systolic array can be applied to the following areas: matrix multiplication, FIR filtering, convolution and correlation, DFT and IDFT. Examples are included to demonstrate how to use the systolic array for each of these operations. With some modification of the PE structure, more applications in signal processing could be expected. This systolic array design gives a good trade-off among simplicity, modularity, flexibility and configurability.