Sub-6 GHz: NR operates in both the lower bands (like 600 MHz) and mid bands (2.5 GHz, 3.5 GHz). These bands provide a balance between coverage and capacity.
mmWave: In addition to sub-6 GHz bands, NR also supports millimeter-wave (mmWave) frequencies (e.g., 24 GHz, 28 GHz, 39 GHz). These offer very high data rates but with limited coverage due to propagation characteristics.
2. Multiple Access Techniques:
Orthogonal Frequency Division Multiple Access (OFDMA): This is the primary multiple access scheme for downlink (DL) in NR. OFDMA allows for flexible allocation of subcarriers to users based on their data rate requirements.
Single Carrier Frequency Division Multiple Access (SC-FDMA): This is used for uplink (UL) transmissions. SC-FDMA helps in achieving better power efficiency and reduced peak-to-average power ratio.
3. Modulation and Coding Schemes:
NR supports various modulation schemes like QPSK, 16QAM, 64QAM, and 256QAM. The choice of modulation depends on the channel conditions, with higher order modulations offering higher data rates but being more susceptible to errors.
Coding schemes like LDPC (Low-Density Parity-Check) and Polar codes are used for forward error correction, improving reliability.
4. Massive MIMO:
NR incorporates Massive MIMO (Multiple Input Multiple Output) technology, allowing for a significant increase in the number of antennas at both the transmitter and receiver ends.
Massive MIMO enhances spectral efficiency, provides better coverage, and supports beamforming techniques to focus signals directionally, improving signal quality and capacity.
5. Latency Reduction:
NR aims to reduce latency significantly compared to previous generations. Ultra-Reliable Low Latency Communication (URLLC) is a feature in NR designed for applications requiring extremely low latency and high reliability, such as industrial IoT applications.
6. Carrier Aggregation:
NR supports carrier aggregation, allowing devices to use multiple frequency bands simultaneously. This increases bandwidth, enhances data rates, and improves overall network performance.
7. Network Slicing:
NR introduces the concept of network slicing, enabling operators to create multiple virtual networks over a single physical infrastructure. This allows customization of network resources and services based on specific application requirements.
8. Beamforming and Tracking:
Beamforming techniques in NR enable the focusing of signals in specific directions, enhancing coverage, and improving signal quality.
NR also supports beam tracking, allowing devices to maintain optimal signal paths as they move, ensuring consistent connectivity.
