ASYMMETRICAL FORWARD/REVERSE TRANSMISSION BANDWIDTH

摘要

A wireless communications system employs code-division multiple access information transmission techniques where the uplink and downlink transmission bandwidths are unequal. The higher bandwidth is an integer multiple of the lower bandwidth. The present system requires a base station and a subscriber unit to have two pseudo-random code generators which can be clocked separately. Alignment of the uplink and downlink pseudo-random spreading codes is achieved by truncating the code sequence for the lower speed link at the conclusion of a complete code sequence for the higher speed link.

主权项

1. An apparatus for wireless communication in a code division multiple access (CDMA) system, comprising:
a first pseudo-random sequence circuit to provide a first pseudo-random code sequence, a second pseudo-random sequence circuit to provide a second pseudo-random code sequence, wherein the second pseudo-random code sequence is longer than the first pseudo-random code sequence; and a combiner to combine output values associated with the first pseudo-random sequence and associated with the second pseudo-random code sequence to form a third pseudo-random sequence; wherein, when the first pseudo-random sequence circuit initializes, the second pseudo-random sequence circuit initializes to truncate the second pseudo-random code sequence, and wherein a length of the first pseudo-random code sequence is a first number of chips, a length of the second pseudo-random code sequence is a second number of chips, the first number of chips being less than the second number of chips, and a length of the third pseudo-random sequence is a third number of chips, the third number of chips being less than a product of the first number of chips and the second number of chips; and a spreading circuit to spread a signal with the third pseudo-random sequence, wherein the signal carries information.