Implementation and experimental results of a three-transmitter three-receiver OFDM/BLAST testbed

A three-transmitter three-receiver orthogonal frequency-division multiplexing Bell Laboratories layered space-time testbed is set up, which achieves a peak data rate of 281.25 Mb/s and a spectral efficiency of 14.4 b/Hz/s. The transmitter of the testbed consists of three signal generators transmitting three independent OFDM signals at 25 Msamples/s synchronously. Three synchronized receiving links are used, each of which includes an RF receiver, an analog-to-digital converter, a digital downconverter, and a PowerPC processor for baseband processing. The performance and complexity of three typical BLAST detection techniques (linear detection, ordered decision feedback detection, and partial decision detection) are evaluated and compared using the data from the experiments conducted in both line-of-sight and non-line-of-sight indoor environments.