System and method for detecting speech transmissions in the presence of control signaling

Claim 2

A receiver apparatus in a digital telecommunication system, said receiver receiving a substantially continuous series of transmission frames containing therein speech transmission and respective frames within said series containing a plurality of control signal transmissions therein, said receiver apparatus comprising: a detector for detecting said series of transmission frames, said detector setting a multiplicity of flags therein for a particular transmission frame, said flags comprising a speech flag set if said particular transmission frame contains speech therein, a control signal detected flag set if said particular transmission frame contains said control signal transmissions therein and a control signal likely flag if said particular transmission frame potentially contains said control signal transmissions therein; and a summation device, attached to said detector, said detector applying said multiplicity of flags to said summation device, whereby said speech transmissions play at said receiver whenever said summation device indicates a speech transmission.

Claim 3

The receiver apparatus according to claim 1, further comprising: a first voice transmission decoder, said first voice decoder receiving said particular transmission frame and setting said speech flag if said particular transmission frame decodes pursuant to a first metric.

Claim 4

The receiver apparatus according to claim 2, wherein said first voice transmission decoder is a Viterbi decoder, said Viterbi decoder forming a multiplicity of candidate frames pursuant to said first metric.

Claim 5

The receiver apparatus according to claim 3, wherein if the best candidate frame metric of said multiplicity of candidate frames is a zero state, said control signal likely flag is set.

Claim 6

The receiver apparatus according to claim 2, further comprising: a second voice transmission decoder, said second voice decoder receiving said decoded particular transmission frame from said first voice decoder, said particular transmission frame being decoded by said first voice decoder, and said second voice decoder setting said speech flag if said decoded particular transmission frame decodes pursuant to a second metric.

Claim 7

The receiver apparatus according to claim 5, where said second voice transmission decoder is a cyclic redundancy code check, said speech flag set if said decoded particular transmission frame passes said cyclic redundancy code check.

Claim 8

The receiver apparatus according to claim 1, wherein said detector further comprises: a control signal transmission decoder, said control signal transmission decoder receiving said particular transmission frame and setting said control signal likely flag if said particular transmission frame decodes pursuant to a third metric forming a candidate control signal frame.

Claim 9

The receiver apparatus according to claim 7, wherein said control signal transmission decoder is a Viterbi decoder, said control signal likely flag being set if said particular transmission frame decodes pursuant to said Viterbi decoder.

Claim 10

The receiver apparatus according to claim 7, further comprising: a fire decoder, said fire decoder receiving said candidate control signal frame and a plurality of prior transmission frames, from said control signal transmission decoder, and setting said control signal detected flag if said fire decoder determines that a valid control signal transmission was received.

Claim 11

The receiver apparatus according to claim 9, further comprising an assembler, said assembler receiving said candidate control signal frame, assembling said candidate control signal frame with said plurality of prior transmission frames, forming an assembled frame group, and forwarding said assembled frame group to said fire decoder.

Claim 12

The receiver apparatus according to claim 10, wherein said assembler assembles four said frames, one being said candidate control signal frame and the remaining three being said prior transmission frames.

Claim 13

The receiver apparatus according to claim 1, wherein said multiplicity of flags received by said summation device comprise said speech flag, an inverted control signal detected flag, and an inverted control signal likely flag, the summation of said multiplicity of flags being set if said particular transmission frame is a speech transmission.

Claim 14

The receiver apparatus according to claim 12, wherein said inverted control signal likely flag comprises the inverted value of the addition of the control signal likely flags for the particular transmission frame and a plurality of previous transmission frames.

Claim 15

The receiver apparatus according to claim 1, further comprising a discontinuous transmission (DTX) mode flag, said DTX mode flag when set indicating insertion of comfort noise in said series of transmission frames for playing at said receiver, said DTX mode flag when not set indicating playing said speech transmissions at said receiver.

Claim 16

The receiver apparatus according to claim 14, wherein when said DTX mode is set and a multiplicity of speech transmission frames are received, said speech transmissions are played at said receiver.

Claim 17

The receiver apparatus according to claim 14, further comprising a speech decoder, said speech decoder decoding said speech transmissions if said speech flag is set.

Claim 18

The receiver apparatus according to claim 16, wherein said speech decoder sets said DTX mode flag when said series of transmission frames enters a DTX period, and wherein, at the end of said DTX period, said detector detects at least two consecutive speech transmission frames prior to playing said speech transmissions.

Claim 19

The receiver apparatus according to claim 1, wherein said control signal transmissions are Fast Associated Control Channel (FACCH) signals within said series of transmission frames.

Claim 20

The receiver apparatus according to claim 18, wherein said FACCH signals comprise four consecutive transmission frames in said series.

Claim 21

The receiver apparatus according to claim 1, wherein said telecommunications system is based upon Satellite Air Interface Specification protocols.

Claim 22

The receiver apparatus according to claim 1, wherein said receiver is within a mobile terminal in wireless communication with a base station.

Claim 23

The receiver apparatus according to claim 1, wherein said receiver is within a base station.

Claim 24

In a digital telecommunications system having a first communication system and a second communication system, the first and second communication systems coupled together by way of a communication channel, a combination with the first and second communication systems of communication circuitry for transmitting and receiving, respectively, a plurality of speech frames therebetween, said circuitry comprising: transmission means within said first communication system, said transmission means generating and transmitting a substantially continuous series of transmission frames containing said speech frame segments therein across said communication channel, said transmission means also generating and transmitting a plurality of transmission frames of a control signal across said communication channel, said control signal having precedence over said speech and a plurality of control signal frames overriding a corresponding plurality of said speech frames; reception means within said second communication system, said reception means for receiving said substantially continuous sequence of transmission frames containing therein said speech frames and said control frames across said communication channel; and detection means within said second communication system, said detection means for detecting said speech and said control signals within a segment of said continuous series of received transmission frames, said detection means identifying speech within a particular transmission frame of said segment by applying a multiplicity of flags to a summation device, said flags comprising a speech flag set if said detection means identifies said particular transmission frame as containing speech, a control signal detected flag set if said detection means identifies said particular transmission frame as containing control signals, and a control signal likely flag set if said detection means identifies said particular transmission frame as potentially containing control signals.

Claim 25

In a digital telecommunications system having a first communication system and a second communication system, the first and second communication systems coupled together by way of a communication channel, a combination with the first and second communication systems of communication circuitry for transmitting and receiving, respectively, a plurality of speech frames therebetween, said circuitry comprising: transmission means within said first communication system, said transmission means generating and transmitting a substantially continuous series of transmission frames containing said speech frame segments therein across said communication channel, said transmission means also generating and transmitting a plurality of transmission frames of a control signal across said communication channel, said control signal having precedence over said speech and a plurality of control signal frames overriding a corresponding plurality of said speech frames; reception means within said second communication system, said reception means for receiving said substantially continuous sequence of transmission frames containing therein said speech frames and said control frames across said communication channel; and detection means within said second communication system, said detection means for detecting said speech and said control signals within a segment of said continuous series of received transmission frames, said detection means identifying speech within a particular transmission frame of said segment by applying a multiplicity of flags to a summation device, said flags comprising a speech flag set if said detection means identifies said particular transmission frame as containing speech, a control signal detected flag set if said detection means identifies said particular transmission frame as containing control signals, and a control signal likely flag set if said detection means identifies said particular transmission frame as potentially containing control signals.

Claim 26

The communication circuitry according to claim 23, wherein said first communication system is a base station and said second communication system is a mobile terminal in wireless communication with said base station across said communication channel.

Claim 27

The communication circuitry according to claim 23, wherein said second communication system is a base station.

Claim 28

The communication circuitry according to claim 23, wherein said control signal is a Fast Associated Control Channel signal.

Claim 29

The communication circuitry according to claim 23, wherein said telecommunications system is based upon Satellite Air Interface Specification protocols.

Claim 30

The communication circuitry according to claim 23, wherein said control signal likely flag is set if said detection means determines that a best candidate frame metric for said particular transmission frame pursuant to a first metric is a zero state.

Claim 31

A digital telecommunications system having a transmitter and a receiver coupled together by way of a communication channel, a substantially continuous series of transmission frames containing speech and a plurality of control signals therein passing across said channel from said transmitter to said receiver across such channel, said control signal having precedence over and overriding said speech, said telecommunications system comprising: a detector, attached to said receiver, for detecting said series of transmission frames, said detector setting a multiplicity of flags, said flags comprising a speech flag set if a particular transmission frame contains speech therein, a control signal detected flag if said particular transmission frame contains said control signals therein and a control signal likely flag if said particular transmission frame potentially contains said control signals therein; and a summation device, attached to said detector, said detector applying said multiplicity of flags to said summation device, whereby speech transmissions play at said receiver whenever said summation device indicates a speech transmission.

Claim 32

A digital telecommunications system having a transmitter and a receiver coupled together by way of a communication channel, a substantially continuous series of transmission frames containing speech and a plurality of control signals therein passing across said channel from said transmitter to said receiver across such channel, said control signal having precedence over and overriding said speech, said telecommunications system comprising: a detector, attached to said receiver, for detecting said series of transmission frames, said detector setting a multiplicity of flags, said flags comprising a speech flag set if a particular transmission frame contains speech therein, a control signal detected flag if said particular transmission frame contains said control signals therein and a control signal likely flag if said particular transmission frame potentially contains said control signals therein; and a summation device, attached to said detector, said detector applying said multiplicity of flags to said summation device, whereby speech transmissions play at said receiver whenever said summation device indicates a speech transmission.

Claim 33

The telecommunications system according to claim 29, wherein said receiver, detector and summation device are within a mobile terminal in wireless communication with said transmitter.

Claim 34

The telecommunications system according to claim 29, wherein said receiver, detector and summation device are within a base station.

Claim 35

The telecommunications system according to claim 29, wherein said control signal is a Fast Associated Control Channel signal.

Claim 36

The telecommunications system according to claim 29, wherein said telecommunications system is based upon Satellite Air Interface Specification protocols.

Claim 37

The telecommunications system according to claim 29, wherein said control signal likely flag is set if said detection means determines that a best candidate frame metric for said particular transmission frame pursuant to a first metric is a zero state.

Claim 40

The method according to claim 35, wherein said first communication system is a base station and said second communication system is a mobile terminal in wireless communication with said base station across said communication channel.

Claim 41

The method according to claim 35, wherein said second communication system is a base station.

Claim 42

The method according to claim 35, wherein said control signal is a Fast Associated Control Channel signal.

Claim 43

The method according to claim 35, wherein said telecommunications system is based upon Satellite Air Interface Specification protocols.

Claim 44

The method according to claim 35, further comprising steps of: calculating a best candidate frame metric for said particular transmission frame pursuant to a first metric; determining if said best candidate frame metric is a zero state; and setting said control likely flag if said best candidate from metric is said zero state.