FR (Full Rate)

Full Rate (FR) is a speech coding standard used in digital cellular networks for voice communication. It is an advanced version of the Half Rate (HR) speech coding standard, which was developed to reduce the bandwidth required for voice communication in cellular networks. The FR speech coding standard is designed to provide high-quality voice communication with a low bit rate.

FR is based on the Regular Pulse Excitation-Long-Term Prediction (RPE-LTP) algorithm, which is a type of speech coding algorithm that uses a combination of linear prediction and codebook-based vector quantization. The RPE-LTP algorithm is used to analyze and compress the speech signal into a digital format that can be transmitted over the network. The FR algorithm is designed to operate at a bit rate of 13 kbps, which is significantly higher than the 6.5 kbps bit rate of the HR algorithm.

The FR algorithm is designed to provide high-quality voice communication in a noisy environment. It uses a variety of techniques to reduce the impact of noise and interference on the speech signal. For example, it uses a post-processing algorithm to remove residual noise from the speech signal, and it employs a formant sharpening technique to enhance the intelligibility of the speech signal.

The FR algorithm is also designed to minimize the delay and jitter in the speech signal. Delay and jitter can cause distortion and loss of synchronization in the speech signal, which can reduce the quality of the voice communication. The FR algorithm uses a frame structure that divides the speech signal into short frames of 20 ms duration. Each frame is coded independently, and the coding parameters are transmitted over the network in real-time. This allows the network to maintain a low delay and jitter, which ensures that the voice communication is clear and smooth.

The FR algorithm uses a multi-rate coding scheme that allows it to adapt to the changing characteristics of the speech signal. The speech signal is analyzed and divided into different frequency bands, and the coding parameters are adjusted for each frequency band. This allows the algorithm to provide high-quality voice communication in a wide range of different acoustic environments.

The FR algorithm also uses a variety of error detection and correction techniques to ensure that the speech signal is transmitted accurately over the network. It uses a cyclic redundancy check (CRC) to detect errors in the transmitted data, and it employs a forward error correction (FEC) technique to correct errors in the data. This helps to ensure that the voice communication is clear and free from errors.

One of the key advantages of the FR algorithm is its high compression efficiency. The algorithm is able to compress the speech signal into a digital format that requires only a small amount of bandwidth for transmission over the network. This makes it possible to support a large number of voice channels on a single cellular network, which helps to reduce the cost of the network and improve its efficiency.

Another advantage of the FR algorithm is its compatibility with other speech coding standards. The algorithm is designed to be backward compatible with the HR speech coding standard, which means that it can be used in networks that support both HR and FR speech coding. This allows network operators to migrate to the FR standard gradually, without having to replace their existing infrastructure.

In conclusion, Full Rate (FR) is a speech coding standard used in digital cellular networks for voice communication. It is an advanced version of the Half Rate (HR) speech coding standard, which was developed to reduce the bandwidth required for voice communication in cellular networks. The FR algorithm is designed to provide high-quality voice communication with a low bit rate, and it uses a variety of techniques to reduce the impact of noise and interference on the speech signal. It is able to compress the speech signal into a digital format that requires only a small amount of bandwidth for transmission over the network, which helps to reduce the cost of the network and improve its efficiency. Furthermore, the FR algorithm is able to adapt to the changing characteristics of the speech signal, which makes it suitable for use in a wide range of different acoustic environments. It is also designed to minimize the delay and jitter in the speech signal, which ensures that the voice communication is clear and smooth.