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An apparatus and method for reducing the effect of noise in a signal handling system which includes a noise-susceptible link (12). The apparatus also includes a first signal processor (13) positioned upstream from the link (12) with a sampled data filter (23) having an inverse high-pass characterist

An apparatus and method for reducing the effect of noise in a signal handling system which includes a noise-susceptible link (12). The apparatus also includes a first signal processor (13) positioned upstream from the link (12) with a sampled data filter (23) having an inverse high-pass characteristic, and a second signal processor (16) positioned downstream from the link (12) with a sampled data first filter (26) having a high-pass characteristic and a second filter (27) having a low-pass characteristic. The two sampled data filters have reciprocal responses and each employ modulo N arithmetic, i.e., when the output reaches a level N it overflows. Thus, the filter (26) downstream of the link (12), which is preferably a digital filter, has a transfer function (P(z)) modulo N, while the filter (23) upstream of the link, also preferably a digital filter, has the inverse transfer function (1/P(z)) modulo N. The second filter (27) downstream of the link (12) has a transfer function which is substantially orthogonal to that of the first downstream filter (26). As a result, signals passing through the system, provided that they lie within the passbank of the second downstream filter (27), are largely unaffected, while noise picked up in the link (12) is confronted by an orthogonal filter pair and is consequently much reduced in amplitude. The link (12) may include a quantizing circuit for restricting the number of bits of the signal transmitted over the link (12), in which case the arrangement in accordance with the invention operates to reduce quantization noise.

대표청구항 ▼

A satellite communications receiver for receiving an information signal over a noise-susceptible link from a transmitter having a digital sampled data transmitter filter using modulo N arithmetic, wherein the receiver includes a digital sample data first receiver filter using modulo N arithmetic, an

A satellite communications receiver for receiving an information signal over a noise-susceptible link from a transmitter having a digital sampled data transmitter filter using modulo N arithmetic, wherein the receiver includes a digital sample data first receiver filter using modulo N arithmetic, and a second receiver filter which, apart from effects resulting from the modulo N arithmetic of the first receiver filter, has a transfer function which is substantially orthogonal to the transfer function of the first receiver filter.