Abstract: Disclosed is a method for operating a code division multiple access communications system, and a system that operates in accordance with the method. The method operates within a coverage area of a base station by assigning a set of spreading codes to individual ones of a plurality of subscriber stations and then, during transmissions within the cell, by periodically hopping amongst spreading code within the set of spreading codes such that at any given time no two subscriber stations operate with the same spreading code. The set of spreading codes may include the all one's spreading code. The step of periodically hopping preferably changes from a currently used spreading code to a next spreading code at a symbol rate or at a multiple of the symbol rate.

Abstract: Disclosed is a method for operating a code division multiple access communications system, and a system that operates in accordance with the method. The method operates within a coverage area of a base station by assigning a set of spreading codes to individual ones of a plurality of subscriber stations and then, during transmissions within the cell, by periodically hopping amongst spreading code within the set of spreading codes such that at any given time no two subscriber stations operate with the same spreading code. The set of spreading codes may include the all one's spreading code. The step of periodically hopping preferably changes from a currently used spreading code to a next spreading code at a symbol rate or at a multiple of the symbol rate.

Abstract: A method and apparatus for constructing a series of PN code sets that can be used for multirate synchronous and quasi-synchronous CDMA systems. The construction technique produces PN codes that are balanced, and that furthermore do not require any synchronization of neighboring base stations. The method is a non-recursive method that uses a permuted orthogonal matrix to modulate permuted orthogonal matrices to create PN codes that support multirate operation. Furthermore, the codes constructed using the method have very good spectral properties (if chosen properly) when the code length, n, is reasonably large.

Abstract: A method is disclosed for operating a fixed wireless system having a radio base unit (RBU) that uses a code division multiple access (CDMA) airlink for communicating with a plurality of subscriber units (SUs). The method includes steps of (a) estimating a signal to noise ratio (SNR) of the FWS; (b) comparing the estimated SNR to a threshold SNR value; and (c) one of allowing service to another SU or not allowing service to another SU based on the result of the step of comparing. The step of estimating preferably uses a normalized SNR, and further employs the use of a null PN code detection technique. More particularly, the step of estimating determines a normalized signal to noise ratio given by Eb/No=20 log (SUT/MUT)-xdB, wherein SUT represents a single user test measurement, wherein MUT represents a multiple user test measurement, and wherein xdB is an adjustment factor. Other types of CDMA systems may also use this technique.

Abstract: Disclosed is a method for operating a fixed wireless system (FWS) having a radio base unit (RBU) that uses a code division multiple access (CDMA) airlink for communicating with a plurality of subscriber units (SUs) within a coverage area of the RBU. The method includes establishing, from a set of pseudonoise (PN) spreading codes, a subset of PN spreading codes that are currently assigned to SUs and a subset of PN spreading codes that are currently not assigned to SUs. The method further ranks the PN spreading codes from the subset of non-assigned PN spreading codes by an amount of interference experienced by the use of each non-assigned PN spreading code, and assigns to an SU requiring a PN spreading code a PN spreading code from the set of non-assigned PN spreading codes that is ranked as having a least amount of interference.