1xEV-DO Measurements
R&S
®
CMW-KG8xx/-KM8xx/-KS8xx
252
User Manual 1173.9511.02 ─ 11
Band
Class
Number
Band Class Name
Channel
Number N
Center Frequency
[MHz]
Band
Class
Group
15
AWS Band
0 to 899
1710 + 0.05 N
1900
16
US 2.5 GHz Band
140 to 1459
2495 + 0.05 N
1900
18
Public Safety Band 700 MHz
0 to 240
787 + 0.05 N
800
19
Lower 700 MHz
0 to 360
698 + 0.05 N
800
3.2.6.2
Channelization
1xEV-DO channels are spread using orthogonal Walsh functions W
n
N
defined in terms
of the order N of the function and the index n ranging from 0 to N-1. This index is also
called channelization code number. The Walsh functions are serially constructed from
a N x N Hadamard matrix, generated by means of the following recursive procedure
defined in 3GPP2 C.S0002:
For the spreading operation the binary symbols of the Walsh function are mapped as
follows: "0" is mapped to +1 and "1" is mapped to "-1".
Orthogonal Variable Spreading Factor (OVSF) codes provide an alternative scheme of
generating codes that preserve orthogonality between channels. They are derived from
a hierarchical tree:
The OVSF spreading factor SF corresponds to the Walsh function order N. For a given
spreading factor SF, Walsh codes and OVSF codes can be derived from each other
via the binary representation of the channelization code numbers. The Walsh code with
code number n is equal to the OVSF code with code number m, where m has the
General Description
深圳德标仪器
135-1095-0799
