Method and apparatus for detecting hangover periods in a TDMA wireless communication system using discontinuous transmission

Claim 3

A method according to claim 1, characterized in that said discontinuous transmission comprises an averaging period (211, 212) with a length of a predetermined number of frame periods, of which at least the last frame period is a frame period belonging to the silence period (208, 209; 303); whereby in said transmission the speech decoder gets an information signal (107, 405) for each frame period, the signal having a first value if the frame period belongs to an information transmission period (200; 301; 302) or to a hangover period (T), and a second value if the frame period belongs to a silence period (208, 209; 303); and in which method the number of frame periods is counted (411) in the receiver until the last frame period (0) of the averaging period (211, 212); the moment when said information signal (405) changes from said first value to said second value is detected; and based on said counted number of frame periods and said detection it is decided whether or not there is a hangover period (T) between said information transmission period (200; 301; 302) and the silence period (208, 209; 303) following the information transmission period.

Claim 4

A speech decoder for the decoding of speech frames received in discontinuous transmission comprising: means (402) performing the speech decoding in order to decode the received speech frame for reproduction; comfort noise generation means (407) to generate synthetic noise for said reproduction; and speech decoding control means (408) to control the speech decoding; whereby said discontinuous transmission comprises temporally sequential frame periods of which some periods will contain a transmitted frame and some periods contain no transmission, constituting information transmission periods (200; 301; 302) comprising at least one frame and containing information given by a user to said transmitter device, and silence periods (208, 209; 303) having a length of at least one frame period and containing other information than that given by the user; whereby there is an irregularly occurring period (T) comprising at least one frame between an information transmission period (200) and the following silence period (208, 209), the irregular period forming a hangover period to determine the information relating to the silence period; characterized in that it comprises means (411) counting the number of frame periods until a predetermined moment; means (410) detecting the beginning of said silence period (208, 209; 303); and means (410) deciding on the basis of said counted number of frame periods and the beginning of the silence period (208, 209; 303) whether or not there is a hangover period (T) of said type between said information transmission period (200; 301; 302) and the silence period (208, 209; 303) following the information transmission period.

Claim 5

A speech decoder for the decoding of speech frames received in discontinuous transmission comprising: means (402) performing the speech decoding in order to decode the received speech frame for reproduction; comfort noise generation means (407) to generate synthetic noise for said reproduction; and speech decoding control means (408) to control the speech decoding; whereby said discontinuous transmission comprises temporally sequential frame periods of which some periods will contain a transmitted frame and some periods contain no transmission, constituting information transmission periods (200; 301; 302) comprising at least one frame and containing information given by a user to said transmitter device, and silence periods (208, 209; 303) having a length of at least one frame period and containing other information than that given by the user; whereby there is an irregularly occurring period (T) comprising at least one frame between an information transmission period (200) and the following silence period (208, 209), the irregular period forming a hangover period to determine the information relating to the silence period; characterized in that it comprises means (411) counting the number of frame periods until a predetermined moment; means (410) detecting the beginning of said silence period (208, 209; 303); and means (410) deciding on the basis of said counted number of frame periods and the beginning of the silence period (208, 209; 303) whether or not there is a hangover period (T) of said type between said information transmission period (200; 301; 302) and the silence period (208, 209; 303) following the information transmission period.

Claim 6

A speech decoder according to claim 3, characterized in that said discontinuous transmission comprises: an averaging period (211, 212) with a length of a predetermined number of frame periods, of which at least the last frame period is a frame period belonging to the silence period (208, 209; 303); whereby in said transmission the speech decoder gets an information signal (107, 405) for each frame period, the signal having a first value if the frame period belongs to an information transmission period (200; 301; 302) or to a hangover period (T) and a second value if the frame period belongs to a silence period (208, 209; 303); said counting means (411) comprise means to count the number of frame periods in the receiver until the last frame period (0) of the averaging period (211, 212); said detection means (410) comprise means to detect the moment when said information signal (405) changes from said first value to said second value; and said decision means (410) comprise means to decide based on said number of frame periods counted by said counting means (411) and said detection performed by said detection means (410) whether or not there is a hangover period (T) of said type between said information transmission period (200; 301; 302) and the silence period (208, 209; 303) following the information transmission period.

Claim 7

A transceiver for a mobile phone system utilizing discontinuous transmission, the transceiver comprising a transmitter branch to transmit messages and a receiver branch to receive messages, the receiver branch having a speech decoder comprising: means (402) performing the speech decoding in order to decode the received speech frame for reproduction; comfort noise generation means (407) to generate synthetic noise for said reproduction; and speech decoding control means (408) to control the speech decoding; whereby said discontinuous transmission comprises temporally sequential frame periods of which some periods will contain a transmitted frame and some periods contain no transmission, constituting information transmission periods (200; 301; 302) comprising at least one frame and containing information given by a user to said transmitter device, and silence periods (208, 209; 303) having a length of at least one frame period and containing other information than that given by the user; whereby there is an irregularly occurring period (T) comprising at least one frame between an information transmission period (200) and the following silence period (208, 209), the irregular period forming a hangover period to determine the information relating to the silence period; characterized in that it comprises means (411) counting the number of frame periods until a predetermined moment; means (410) detecting the beginning of said silence period (208, 209; 303); and means (410) deciding on the basis of said counted number of frame periods and the beginning of the silence period (208, 209; 303) whether or not there is a hangover period (T) of said type between said information transmission period (200; 301; 302) and the silence period (208, 209; 303) following the information transmission period.

Claim 8

A transceiver for a mobile phone system utilizing discontinuous transmission, the transceiver comprising a transmitter branch to transmit messages and a receiver branch to receive messages, the receiver branch having a speech decoder comprising: means (402) performing the speech decoding in order to decode the received speech frame for reproduction; comfort noise generation means (407) to generate synthetic noise for said reproduction; and speech decoding control means (408) to control the speech decoding; whereby said discontinuous transmission comprises temporally sequential frame periods of which some periods will contain a transmitted frame and some periods contain no transmission, constituting information transmission periods (200; 301; 302) comprising at least one frame and containing information given by a user to said transmitter device, and silence periods (208, 209; 303) having a length of at least one frame period and containing other information than that given by the user; whereby there is an irregularly occurring period (T) comprising at least one frame between an information transmission period (200) and the following silence period (208, 209), the irregular period forming a hangover period to determine the information relating to the silence period; characterized in that it comprises means (411) counting the number of frame periods until a predetermined moment; means (410) detecting the beginning of said silence period (208, 209; 303); and means (410) deciding on the basis of said counted number of frame periods and the beginning of the silence period (208, 209; 303) whether or not there is a hangover period (T) of said type between said information transmission period (200; 301; 302) and the silence period (208, 209; 303) following the information transmission period.

Claim 9

A transceiver according to claim 5, characterized in that said discontinuous transmission comprises: an averaging period (211, 212) with a length of a predetermined number of frame periods, of which at least the last frame period is a frame period belonging to the silence period (208, 209; 303); whereby in said transmission the speech decoder gets an information signal (107, 405) for each frame period, the signal having a first value if the frame period belongs to an information transmission period (200; 301; 302) or to a hangover period (T) and a second value if the frame period belongs to a silence period (208, 209; 303); said counting means (411) comprise means to count the number of frame periods in the receiver until the last frame period (0) of the averaging period (211, 212); said detection means (410) comprise means to detect the moment when said information signal (405) changes from said first value to said second value; and said decision means (410) comprise means to decide based on said number of frame periods counted by said counting means (411) and said detection performed by said detection means (410) whether or not there is a hangover period (T) of said type between said information transmission period (200; 301; 302) and the silence period (208, 209; 303) following the information transmission period.

Claim 10

A transceiver according to claim 5, characterized in that it is a mobile phone.

Claim 11

A transceiver according to claim 5, characterized in that it is base station.