Deviations from LTE release 8

As the eNB and UE provide only minimal LTE release 8 (Rel 8) PHY/MAC functionality, it is particularly important to note that the DL frame structure and control channels differ slightly. Differences include:

• PDCCH is always in the second OFDM-symbol (position is variable according to Rel. 8),
• PHICH (HARQ Indicator Channel) is not in the first OFDM symbol and has a different structure/content,
• PCFICH (Control Format Indicator Channel) is not supported, and
• PBCH (Broadcast Channel) is not supported.

Further, the OFDM scheme is used in the uplink. Also, 5 MHz and 10 MHz mode are not supported, thus the testbed operates in 20 MHz mode only.

An overview of the uplink and downlink processing chains can be seen below:

Uplink and Downlink Processing Chain