Novel techniques of a list sphere decoder for high throughput

Since finding the nearest point in a lattice for multi-input multi-output (MIMO) channels is NP-hard, simplified algorithms such as a sphere decoder (SD) have been proposed. List sphere decoder (LSD), which is a modified version of SD, allows soft information to be extracted for channel decoding and iterative detection/decoding. In this paper, recently proposed efficient methods for reducing the computational complexity of a sphere decoder (SD) and a list sphere decoder (LSD) with depth-first tree searching are summarized. Numerous simulations have been carried out and comparison has been made based on of the average number of processing cycles.