A 16-core multi-input multi-output (MIMO) decoder for agile communication systems is implemented in a low-VT 90nm CMOS technology. This chip implements the sphere decoding algorithm and is highly flexible to support multiple configurations: antenna arrays from 2x2 to 16x16, modulations from BPSK to 64QAM, and up to 128 data streams. Operating at 16MHz, the chip provides 50GOPS (l2-bit add equivalent) in the 16 x16, 64QAM mode . It consumes 2.89mW of power with a 321mV supply voltage, resulting in a power efficiency of 17.3GOPS/mW. At 256MHz, the peak data rate exceeds 1.5Gbps over a 16MHz channel.