A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output wireless downlink. A storage medium encoded with machine-readable computer program code for measuring table sag of a table may include instructions for causing a computer to implement the method. The signal is transmitted on a commercial FM broadcast station such that substantially the entire spectrum of the transmission comprises the digital data frames. An upstream face of the valve seat is downstream of an upstream end of the tubular body and a downstream face of the valve seat is upstream of a downstream end of the tubular body. Further, the imaging lens satisfies a predetermined conditional expression.