A method to be carried out by a base station in a cellular network having a reuse factor of three for uplink pilot signals to be used for channel measurement, and serving a cell of reuse class A, a cell of the network being one of three reuse classes A, B, and C corresponding to the reuse factor, the cellular network defining three different sets U = { u i}, V = { v i}, W = { w i} of pilot signals, a base station serving a class A cell allocating pilot signals from the set U, a base station serving a class B cell allocating pilot signals from the set V, and a base station serving a class C cell allocating pilot signals from the set W, wherein the pilot signals in each of the sets U, V, W viewed as vectors constitute an orthogonal basis, wherein three pilot signals forming a first subset of U are orthogonal to six pilot signals forming a subset of W, three pilot signals forming a second subset of U disjoint from the first subset of U are orthogonal to six pilot signals forming a subset of V, three pilot signals from said subset of V are orthogonal to the six pilot signals of the first and second subset of U, three pilot signals from said subset of W are orthogonal to the six pilot signals of the first and second subset of the set U, the method comprising: classifying each mobile station currently within a cell of reuse class A served by the base station as a center mobile, a peripheral mobile near a class B cell, or a peripheral mobile near a class C cell; allocating pilot signals to a mobile classified as peripheral near a class B cell a pilot signal of the second subset of U, to a mobile classified as peripheral near a class C cell a pilot signal of the first subset of U, and to a mobile classified as a center mobile one of the remaining pilot signals of U; receiving a pilot signal transmitted over a wireless radio frequency propagation channel from at least one mobile station belonging to the cell served by the base station; and deriving information about the propagation channel from the transmitted and received pilot signal using knowledge of the pilot signals in the set U. the pilot signals in each of the sets U, V, W viewed as vectors constitute an orthogonal basis, wherein three pilot signals forming a first subset of U are orthogonal to six pilot signals forming a subset of W, three pilot signals forming a second subset of U disjoint from the first subset of U are orthogonal to six pilot signals forming a subset of V, three pilot signals from said subset of V are orthogonal to the six pilot signals of the first and second subset of U, three pilot signals from said subset of W are orthogonal to the six pilot signals of the first and second subset of the set U, classifying each mobile station currently within a cell of reuse class A served by the base station as a center mobile, a peripheral mobile near a class B cell, or a peripheral mobile near a class C cell; allocating pilot signals to a mobile classified as peripheral near a class B cell a pilot signal of the second subset of U, to a mobile classified as peripheral near a class C cell a pilot signal of the first subset of U, and to a mobile classified as a center mobile one of the remaining pilot signals of U; receiving a pilot signal transmitted over a wireless radio frequency propagation channel from at least one mobile station belonging to the cell served by the base station; and deriving information about the propagation channel from the transmitted and received pilot signal using knowledge of the pilot signals in the set U.