5.11 High-band gain generation

26.1903GPPAdaptive Multi-Rate - Wideband (AMR-WB) speech codecSpeech codec speech processing functionsTranscoding functionsTS

In order to compute the high band gain for 23.85 kbit/s mode, 16 kHz input speech is filtered through a band-pass FIR filter HHB(z) which has the passband from 6.4 to 7 kHz. The high band gain gHB is obtained by

( 58)

where sHB(i) is band-pass filtered input speech and sHB2(i) is high-band speech synthesis obtained from high-band excitation uHB2(i) filtered through high-band synthesis filter AHB(z) described in Section