Patent attributes
A combiner for use in a diversity radio receiver (FM) which receives a plurality of diversity I and Q modulated signals each carrying I and Q information signals through spatially separated antennas, the received I and Q signal pairs being digitized at a sampling rate T and converted to baseband I and Q signals. Each converted I and Q signal pair represents a diversity I and Q vector which is input to the combiner. A discriminator is provided for each sample stream of diversity I and Q vectors input to the combiner. Each discriminator produces, for each sample, an output discriminated I and Q vector (IΔ, QΔ) having a phase representative of the frequency of the information signal and an amplitude proportional to the power of the information signal. Adders separately add together the discriminated I signals (IΔ) to produce a combined discriminated I signal (IcΔ) and the discriminated Q signals (QΔ) to produce a combined discriminated Q signal (QcΔ), whereby the combined discriminated I and Q signals represent a combined discriminated vector (IcΔ, QcΔ) having a phase determined by one or more of the phases of said diversity I and Q vectors depending upon the relative powers of said diversity I and Q vectors. A phase accumulator adds to an accumulation vector, over successive samples, the phases of the combined discriminated vectors (IcΔ, QcΔ) to produce an output combined I and Q signal pair (Ic, Qc).
