Hongyan

Expert Opinion

Expert Opinion
Short LTE articles and opinions by our team of Subject Matter Experts (SMEs)
  • Hongyan

    How to calculate peak data rate in LTE?

    • 12 Comments
    You may hear it many times that the peak data rate of LTE is about 300Mbps? How is the number calculated? What are the assumptions behind? Let's estimate it in a simple way. Assume 20 MHz channel bandwidth, normal CP, 4x4...
  • Hongyan

    PDCCH Construction

    • 9 Comments
    The PDCCH (Physical Downlink Control Channel) in LTE carries UE-specific scheduling assignments for Downlink (DL) resource allocation, Uplink (UL) grants, PRACH (Physical Random Access Channel) responses, UL power control commands...
  • Hongyan

    CQI Reporting in LTE

    • 2 Comments
    CQI (Channel Quality Indication) report is an important element of LTE and has significant impact on the system performance. There are two types of CQI report in LTE: periodic and aperiodic. The periodic CQI report is ...
  • Hongyan

    Physical Hybrid-ARQ Indicator Channel (PHICH)

    • 4 Comments
    The Physical Hybrid-ARQ Indicator Channel (PHICH) in the downlink carries Hybrid ARQ (HARQ) acknowledgements (ACK/NACK) for uplink data transfers. PHICHs are located in the first OFDM symbol of each subframe. (Note that our...
  • Hongyan

    Sounding Reference Signal

    • 2 Comments
    LTE defines an optional sounding reference signal (SRS) in the UL. What is it for? UL channel quality, timing advance, and more. SRS is transmitted by the UE using a known sequence, similar to UL demodulation reference signal...
  • Hongyan

    Cell Size Configuration in Random Access Procedure (I) - Preamble Format

    • 2 Comments
    When we talk about the cell size, we usually think of RF coverage first. The cell radius is also related to the parameter configuration for the random access procedure, such as the preamble format and cyclic shift. Let's...
  • Hongyan

    Cell Size Configuration in RACH (II) – Cyclic Shift

    • 1 Comments
    We have discussed the preamble format configuration vs. the maximum cell radius during the random access procedure. For example, Preamble Format 0 supports a maximum cell radius of 14.5 km. Another random access parameter that...