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UBS EGPRS2-B Uplink modulation and coding scheme

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UBS EGPRS2-B (Enhanced General Packet Radio Service 2-B) in the telecommunications standards. However, I can provide you with an explanation of the uplink modulation and coding scheme used in EGPRS (Enhanced GPRS), which is an enhancement of the General Packet Radio Service (GPRS) used in 2G cellular networks.

EGPRS, also known as GPRS Class 32 or 2.5G, is an extension of the GPRS technology that introduced higher data rates and improved efficiency for data transmission over 2G networks. EGPRS uses a combination of various modulation and coding schemes to achieve higher throughput compared to the original GPRS.

In EGPRS, the uplink modulation and coding scheme define how data is modulated and encoded before transmission from the mobile device (user equipment) to the base station (Node B). The modulation scheme determines how the data is converted into radio signals, and the coding scheme determines how the data is protected against errors during transmission.

EGPRS uses two primary modulation schemes for uplink data transmission:

  1. Gaussian Minimum Shift Keying (GMSK): GMSK is the modulation scheme used in the initial GPRS implementation. It is a type of continuous phase modulation that provides efficient use of radio spectrum but has limited data rates. In EGPRS, GMSK is typically used for voice and low-rate data services.
  2. 8PSK (Phase Shift Keying): 8PSK is an enhanced modulation scheme introduced in EGPRS to achieve higher data rates. It allows eight different phase angles to represent data symbols, enabling higher data throughput compared to GMSK. 8PSK is used for higher data rate services in EGPRS.

EGPRS employs a combination of coding schemes to protect data against errors during transmission. The coding schemes are specified by their coding scheme index (CS) values, where higher CS values correspond to higher error correction capabilities but lower data throughput.

Coding schemes used in EGPRS uplink include:

  1. CS-1: This coding scheme provides the highest level of error correction, making it suitable for transmitting data in environments with poor radio conditions. However, it offers the lowest data throughput.
  2. CS-2: CS-2 provides a moderate level of error correction and higher data rates compared to CS-1.
  3. CS-3: CS-3 offers a good balance between error correction and data throughput, making it suitable for various applications.
  4. CS-4: CS-4 provides the highest data throughput but sacrifices error correction capabilities, making it suitable for transmitting data in good radio conditions.

The choice of coding scheme depends on the network's radio conditions and the required data rates for specific services. The EGPRS system dynamically adjusts the coding scheme based on the radio link quality to optimize the data transmission efficiency.

Conclusion:

EGPRS, an extension of GPRS in 2G cellular networks, utilizes various modulation and coding schemes for uplink data transmission. The uplink modulation schemes include GMSK for voice and low-rate data and 8PSK for higher data rates. Coding schemes (CS-1 to CS-4) are used to protect data against errors during transmission, with higher CS values providing better error correction but lower data throughput. The dynamic adaptation of modulation and coding schemes helps optimize data transmission efficiency based on radio conditions and required data rates in EGPRS.