# US 5,706,282 A · Asymmetric speech coding for a digital cellular communications system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,706,282 A - Document ID: US5706282A - Status: Granted - Kind: A - Application number: 08/345,148 - Filed: 1994-11-28 - Granted: 1998-01-06 - Earliest claimed: 1994-11-28 - Assignees: Lucent Technologies Inc. - Inventors: Min I. Chung - Web page: https://patentgrep.com/patent/US5706282A ## CPC - H04W 52/28: using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non-transmission - H04L 1/00: Arrangements for detecting or preventing errors in the information received {(correcting synchronisation H04L7/00)} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A digital cellular communication system provides an asymmetric speech coder for improving audio quality in the uplink channel. A high rate speech coder is provided in the uplink of the digital cellular communication system to improve the audio quality. To compensate for the higher band width consumed by this high rate speech coder, the uplink uses a channel code, such as a convolutional code, that generates fewer symbols per each input bit, thereby consuming less bandwidth. The loss of coding gain as a result of the change in the convolutional code is compensated for by applying a special power control strategy. The power control strategy increases the transmit power for transceivers using the asymmetric speech coder. ## Claims ### Claim 1 A cellular transceiver, for providing enhanced audio quality cellular communications, comprising: speech decoder means for decoding downlink user communications coded with a speech code at a first rate; and speech coder means for coding uplink user communications with a speech code at a second rate that is higher than said first rate; wherein the second rate of said uplink speech coder results in enhanced quality audio communications while not impacting bandwidth consumption of the downlink. ### Claim 2 (depends on 1) The cellular transceiver of claim 1, further comprising: means for convolutionally coding user communications at a rate that is selected to compensate for the difference between said first and second rates; and means for transmitting said speech coded, convolutionally coded user communications at an increased power level to compensate for lost coding gain resulting from said altered convolutional coding rate. ### Claim 3 (depends on 2) The cellular transceiver of claim 2, further comprising: means for receiving user communications from a user; and means for digitizing said user communications prior to speech coding. ### Claim 4 (depends on 2) The cellular transceiver of claim 2, further comprising: means for receiving control signals to control said power level to optimize channel capacity. ### Claim 5 (depends on 1) The cellular transceiver of claim 1, further comprising data output means for providing downlink user communications to a user of the transceiver. ### Claim 6 (depends on 1) The cellular transceiver of claim 1, wherein said second rate is 13 kbps. ### Claim 7 (depends on 6) The cellular transceiver of claim 6, wherein said first rate is 8 kbps. ### Claim 8 (depends on 2) The cellular transceiver of claim 2, wherein said first rate is 8 kbps, said second rate is 13 kbps, said convolutional code rate is 1/2 and said power level is increased by 0.5 dB. ### Claim 9 (depends on 1) The cellular transceiver of claim 1, further comprising: receiver means for receiving said downlink user communications; decoder means for decoding downlink user communications coded with a convolutional code. ### Claim 10 A system for providing enhanced quality digital cellular communications, comprising: a cellular transceiver for allowing a first user to communicate with a second user via a cellular communications system; a base station for relaying user communications between said cellular transceiver and another transceiver; and an asymmetric speech coder for providing speech coding of user communications between said cellular transceiver and said base station, said asymmetric speech coder comprising: speech decoder means for decoding downlink user communications coded with a speech code at a first rate, and speech coder means for coding uplink user communications with a speech code at a second rate that is higher than said first rate; wherein the second rate of said uplink speech coder results in enhanced quality audio communications while not impacting bandwidth consumption of the downlink. ### Claim 11 A digital cellular communications system for providing enhanced audio quality of user communication, comprising: a base station for relaying user communications between a first user and a second user, wherein said first user is communicating via a cellular transceiver; an asymmetric communications channel for transferring user communications between said cellular transceiver and said base station, said asymmetric communications channel comprising: an uplink data path for transmitting user communications from said cellular transceiver to said base station at a first speech code rate, a downlink data path for transmitting user communications from said base station to said cellular transceiver at a second speech code rate, wherein said first speech code rate is higher than said second speech code rate; a downlink channel, employing a speech code at a first rate; an uplink channel, employing a speech code at a second rate higher than said first rate; means for employing a convolution code to said uplink channel, wherein a rate of said convolution code is selected to compensate for the difference between said first and second rates; and means for transmitting data on said uplink channel at an increased transmit power to compensate for said rate of said convolutional code.