Method and device for determining a decoding mode of in-band signaling

摘要

In the field of communications, a method and a device for determining a decoding mode of in-band signaling are provided, which improve accuracy of in-band signaling decoding. The method includes: calculating a probability of each decoding mode of in-band signaling of a received signal at a predetermined moment by using a posterior probability algorithm; and from the calculated probabilities of the decoding modes, selecting a decoding mode having a maximum probability value as a decoding mode of the in-band signaling of the received signal at the predetermined moment. The method and the device are mainly used in a process for determining a decoding mode of in-band signaling in a speech frame transmission process.

主权项

1. A method for determining a decoding mode of in-band signaling, the method comprising:
calculating, by a mobile station, a probability of each decoding mode of in-band signaling of a signal received at the mobile station at a predetermined moment by using a posterior probability algorithm by:
obtaining, according to a posterior probability principle, a probability formula for calculating the probability of the decoding mode of the in-band signaling of the received signal at the predetermined moment:p(stk=m⁢rk)=p(rk⁢stk=m)⁢p⁡(stk=m)p⁡(rk) wherein st k=m, m=0, 1, 2, 3, which is one of four in-band signaling decoding modes at a moment k, and rk is a received signal vector,taking logarithms of two sides of the probability formula, and simplifying the probability formula according to a relationship between the received signal and a demodulated soft value to obtain a simplified probability formula:ln⁢⁢p(stk=m⁢rk)⇔∑i=03⁢λki⁢ski2+ln⁢⁢p⁡(stk=m) wherein stk=m, m=0, 1, 2, 3, which is one of four in-band signaling decoding modes at a moment k, λ is a demodulated soft value of the received signal, and s is encoded data of a sent signal, andcalculating a logarithmic priori probability of the decoding mode of the in-band signaling of the received signal at the predetermined moment, and substituting the logarithmic priori probability into the simplified probability formula to obtain a probability of a corresponding decoding mode of the received signal at the predetermined moment; and selecting, at the mobile station, from calculated probabilities of decoding modes, a decoding mode having a maximum probability value as a decoding mode of the in-band signaling of the received signal at the predetermined moment.