Zadoff chu sequence in LTE
Zadoff chu sequence often called as CAZAC sequence is popular in LTE technology.
Zadoff chu sequence possess following features.
- It has small variation in time and hence it will add to good Power amplification properties of the complex modulated signal of the LTE modem.
-It has small variation in frequency hence channel estimation at receiver will be simple.
-It has low cross correlation property hence it produces small inter cell interference.
Zadoff chu sequence is defined using following mathematical equation
Zadoff chu sequence Equation
Zadoff chu sequence properties:
-It has constant amplitude.
-It has zero circular auto correlation.
-It has flat frequency domain response.
-circular cross correlation between two zadoff chu sequence is low.
-It has constant amplitude provided, L is a prime number.
LTE physical signals/channels where Zadoff chu is used
P-SS: Primary synchronization signal,Zadoff chu sequence is used for this signal.
RS: Reference Signal, used both in uplink and downlink, Zadoff chu sequence is used.
PUCCH: Physical Uplink Control Channel, Zadoff chu sequence is used.