tokens: ['Since', 'the', 'powerdelayprofile', 'PDP', 'in', 'a', 'reverberation', 'chamber', 'can', 'take', 'the', 'shape', 'of', 'exponential', 'decay', 'the', 'RMS', 'delay', 'spread', 'is', 'the', 'only', 'parameter', 'needed', 'to', 'characterize', 'the', 'chamber', 'PDP', 'From', 'calibration', 'data', 'the', 'RMS', 'delay', 'spread', 'of', 'the', 'current', 'setup', 'can', 'be', 'calculated', 'This', 'should', 'be', 'used', 'to', 'tune', 'the', 'RMS', 'delay', 'spread', 'to', 'what', 'is', 'specified', 'For', 'tuning', 'of', 'the', 'reverberation', 'chamber', 'to', 'a', 'specific', 'radio', 'channel', 'condition', 'the', 'RMS', 'delay', 'spread', 'can', 'be', 'calculated', 'in', 'either', 'of', 'two', 'ways', 'The', 'first', 'alternative', 'is', 'the', 'direct', 'method', 'where', 'the', 'frequency', 'response', 'of', 'the', 'chamber', 'is', 'Fourier', 'transformed', 'to', 'the', 'time', 'domain', 'and', 'a', 'standard', 'calculation', 'of', 'RMS', 'delay', 'spread', 'is', 'performed', 'on', 'the', 'time', 'domain', 'data', 'The', 'second', 'alternative', 'is', 'the', 'simplified', 'method', 'where', 'the', 'relationship', 'between', 'RMS', 'delay', 'spread', 'coherence', 'bandwidth', 'and', 'average', 'power', 'transfer', 'function', 'of', 'the', 'chamber', 'is', 'used', 'The', 'relationship', 'between', 'RMS', 'delay', 'spread', 'and', 'average', 'power', 'transfer', 'function', 'of', 'the', 'chamber', 'is', 'given', 'by']