Patent ID: 6954481

Claim:
Apparatus for use in a base station in an orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access wireless system comprising: a sequence generator for generating one or more pilot tone hopping sequences each including pilot tones, said pilot tones each being generated at frequency and time instants in a time-frequency grid; a waveform generator, responsive to said one or more pilot tone hopping sequences, for generating a waveform for transmission; wherein said sequence generator generates each of said one or more pilot tone hopping sequences in accordance with S i ={f 0 S i , f 1 S i , . . . f k S i , . . . }, for i=1, . . . N pil ; and wherein f k S i =Z{(a(k mod T)+s i )mod p+d}, where “k” is a time instant index, “T”, “a”, “S i ”and “d”are integer constants, “p” is a prime constant, and “Z” is a permutation operator.