Maximum-likelihood detection (MLD) algorithm is the optimal detection scheme for vertical Bell Laboratories layered space-time (V-BLAST) system. However, it is generally infeasible to implement MLD algorithm in practical systems due to its high computational complexity. In this paper, we utilize two parallel interference cancellation techniques including pre-cancellation algorithm and post-cancellation algorithm to simplify MLD algorithm to a computationally efficient suboptimal detection algorithm, herein called generalized parallel interference cancellation (GGPIC) algorithm. Numerical analysis shows GPIC algorithm can approximately achieve the MLD performance with considerably low and stable computational complexity. Since most steps of GPIC algorithm are parallel, it can be accelerated significantly via parallel processing methods. With near-optimal performance, stable and low complexity and fast processing speed, it is typically suitable for real-time high-speed systems.