Does 16-QAM Provide an Alternative to a Half-Rate GSM Speech Codec?

Webb, W T, Hanzo, L, Salammi, R and Steele, R (1991) Does 16-QAM Provide an Alternative to a Half-Rate GSM Speech Codec? In, IEEE VTC'91, St. Louis, Miisouri, USA, 19 - 22 May 1991. , 511-516.


[img] PDF
Download (492Kb)


The computational complexity, speech-quality, spectral efficiency and robustness trade-offs of speech transmission schemes for personal communications networks (PCNs) are addressed. Differentially encoded star 16-QAM arrangements with and without oversampling and diversity are compared in terms of robustness to the parallel frequency division multiplex (FDM) 16-QAM system to find the most appropriate modern scheme. The 13.4 <i>kbps</i> regular pulse <i>RPE-LTP</i> speech codec is subjected to rigorous bit sensitivity analysis in terms of both cepstral distance (CD) and segmental signal to ratio (SEGSNR) degradations. A twin-class embedded binary Bose-Chaudhuri-Hocqunghem (BCH) bit protection scheme is devised to improve robustness. The 6.2 kBd system proposed guarantees low-complexity, high-quality speech transmissions in a bandwidth of 12 kHz for vehicular speeds of 30 mph and channel signal to ratios (SNRs) in excess of 25 dB, a value readily maintained in microcellular PCNs. Wehn using diversity, our system has similar robustness to the 11.4 kbps quadruple-complexity, lower speech-quality code excited linear predictive speech codec/convolutional coding/minimum shift keying (CELP/CC/MSK) benchmarker utilised. Yes, 16-QAM does provide an attractive alternative to half-rate speech coding.

Item Type: Conference or Workshop Item (Paper)
Additional Information: Event Dates: 19-22 May 1991 Organisation: IEEE Address: St. Louis, Missouri, USA
Divisions : Faculty of Physical Sciences and Engineering > Electronics and Computer Science > Southampton Wireless Group
ePrint ID: 251397
Accepted Date and Publication Date:
May 1991Published
Date Deposited: 14 Sep 2001
Last Modified: 31 Mar 2016 13:52
Further Information:Google Scholar

Actions (login required)

View Item View Item

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics